Merge branch 'usrp_e100_devel' of ettus.sourcerepo.com:ettus/uhdpriv into usrp_e100_devel

Conflicts:
	host/lib/usrp/usrp_e100/clock_ctrl.cpp

34 files changed, 528 insertions, 1276 deletions

diff --git a/host/docs/coding.rst b/host/docs/coding.rst
index 7533445ea..ecca4e8b8 100644
--- a/host/docs/coding.rst
+++ b/host/docs/coding.rst
@@ -23,40 +23,10 @@ The device API provides ways to:
 See the documentation in *device.hpp* for reference.
 
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-High-Level: The single usrp
-^^^^^^^^^^^^^^^^^^^^^^^^^^^
-The goal of the single usrp API is to wrap high level functions around the device properties.
-The single usrp provides a fat interface to access the most common properties.
-The single usrp provides ways to:
-
-* Set and get daughterboard gains.
-* Set and get daughterboard antennas.
-* Set and get the streaming rates.
-* Tune the DSPs and daughterboards.
-* Issue stream commands.
-* Set the clock configuration.
-* Set the usrp time registers.
-* Get the underlying device (as discussed above).
-
-See the documentation in *usrp/single_usrp.hpp* for reference.
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^
 High-Level: The multi usrp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-The multi usrp API provides a wrapper around a device that represents several motherboards.
-This API provides convenience calls just like the single usrp,
-however the calls either work across all channels in the configuration,
-or take a channel argument to specify which channel to configure.
-The multi usrp provides ways to:
-
-* Set and get the sample rate across all channels.
-* Issue a stream command across all channels.
-* Set the time registers across all channels.
-* Set and get individual daughterboard gains.
-* Set and get individual daughterboard antennas.
-* Tune individual DSPs and daughterboards.
-* Get the underlying device (as discussed above).
-
+The Multi-USRP class provides a FAT interface to a single USRP with
+one or more channels, or multiple USRPs in a homogeneous setup.
 See the documentation in *usrp/multi_usrp.hpp* for reference.
 
 ------------------------------------------------------------------------
diff --git a/host/docs/usrp2.rst b/host/docs/usrp2.rst
index 2ee49646f..70101bd87 100644
--- a/host/docs/usrp2.rst
+++ b/host/docs/usrp2.rst
@@ -81,7 +81,7 @@ The safe-mode button is a pushbutton switch (S2) located inside the enclosure.
 To boot into the safe image, hold-down the safe-mode button while power-cycling the device.
 Continue to hold-down the button until the front-panel LEDs blink and remain solid.
 
-When in safe-mode, the USRP-N Series will always have the IP address 192.168.10.2
+When in safe-mode, the USRP-N device will always have the IP address 192.168.10.2
 
 ------------------------------------------------------------------------
 Setup networking
@@ -154,31 +154,53 @@ Run the following commands:
     cd <prefix>/share/uhd/utils
     sudo ./usrp2_recovery.py --ifc=eth0 --new-ip=192.168.10.3
 
+------------------------------------------------------------------------
+Communication problems
+------------------------------------------------------------------------
+When setting up a development machine for the first time,
+you may have various difficulties communicating with the USRP device.
+The following tips are designed to help narrow-down and diagnose the problem.
+
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Debugging networking problems
+Firewall issues
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-**Disable the firewall:**
-If uhd_find_devices gives you nothing
-but uhd_find_devices --args addr=192.168.10.2 yeilds a discovered device,
+When the IP address is not specified,
+the device discovery sends broadcast UDP packets from each ethernet interface.
+Many firewalls will block the replies to these broadcast packets.
+If disabling your system's firewall,
+or specifying the IP address yeilds a discovered device,
 then your firewall may be blocking replies to UDP broadcast packets.
+If this is the case, we recommend that you disable the firewall,
+or create a rule to allow all incoming packets with UDP source port 49152.
+
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Ping the device
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The USRP will reply to icmp echo requests.
+A successful ping response means that the device has booted properly,
+and that it is using the expected IP address.
 
-**Ping the USRP2:**
-The USRP2 will reply to icmp echo requests.
 ::
 
     ping 192.168.10.2
 
-**Monitor the serial output:**
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Monitor the serial output
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Read the serial port to get debug verbose from the embedded microcontroller.
-Use a standard USB to 3.3v-level serial converter at 230400 baud.
 The microcontroller prints useful information about IP addresses,
-MAC addresses, control packets, and fast-path settings.
+MAC addresses, control packets, fast-path settings, and bootloading.
+Use a standard USB to 3.3v-level serial converter at 230400 baud.
+Connect GND to the converter ground, and connect TXD to the converter receive.
+The RXD pin can be left unconnected as this is only a one-way communication.
 
 * **USRP2:** Serial port located on the rear edge
 * **N210:** Serial port located on the left side
 
-**Monitor the host network traffic:**
-Use wireshark to monitor packets sent to and received from the USRP2.
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Monitor the host network traffic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+Use wireshark to monitor packets sent to and received from the device.
 
 ------------------------------------------------------------------------
 Addressing the device
diff --git a/host/examples/benchmark_rx_rate.cpp b/host/examples/benchmark_rx_rate.cpp
index c49d8bff0..118bf413c 100644
--- a/host/examples/benchmark_rx_rate.cpp
+++ b/host/examples/benchmark_rx_rate.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright 2010 Ettus Research LLC
+// Copyright 2010-2011 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -17,7 +17,7 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <boost/math/special_functions/round.hpp>
 #include <boost/program_options.hpp>
 #include <boost/format.hpp>
@@ -27,19 +27,19 @@
 namespace po = boost::program_options;
 
 static inline void test_device(
-    uhd::usrp::single_usrp::sptr sdev,
+    uhd::usrp::multi_usrp::sptr usrp,
     double rx_rate_sps,
     double duration_secs
 ){
-    uhd::device::sptr dev = sdev->get_device();
+    const size_t max_samps_per_packet = usrp->get_device()->get_max_recv_samps_per_packet();
     std::cout << boost::format("Testing receive rate %f Msps (%f second run)") % (rx_rate_sps/1e6) % duration_secs << std::endl;
 
     //allocate recv buffer and metatdata
     uhd::rx_metadata_t md;
-    std::vector<std::complex<float> > buff(dev->get_max_recv_samps_per_packet());
+    std::vector<std::complex<float> > buff(max_samps_per_packet);
 
     //flush the buffers in the recv path
-    while(dev->recv(
+    while(usrp->get_device()->recv(
         &buff.front(), buff.size(), md,
         uhd::io_type_t::COMPLEX_FLOAT32,
         uhd::device::RECV_MODE_ONE_PACKET
@@ -55,9 +55,9 @@ static inline void test_device(
     uhd::time_spec_t initial_time_spec;
     uhd::time_spec_t next_expected_time_spec;
 
-    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
+    usrp->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
     do {
-        size_t num_rx_samps = dev->recv(
+        size_t num_rx_samps = usrp->get_device()->recv(
             &buff.front(), buff.size(), md,
             uhd::io_type_t::COMPLEX_FLOAT32,
             uhd::device::RECV_MODE_ONE_PACKET
@@ -89,18 +89,19 @@ static inline void test_device(
             got_first_packet = true;
         }
 
-        total_lost_samples += boost::math::iround(rx_rate_sps*(md.time_spec - next_expected_time_spec).get_real_secs());
+        double approx_lost_samps = rx_rate_sps*(md.time_spec - next_expected_time_spec).get_real_secs();
+        total_lost_samples += std::max(0, boost::math::iround(approx_lost_samps));
         next_expected_time_spec = md.time_spec + uhd::time_spec_t(0, num_rx_samps, rx_rate_sps);
 
     } while((next_expected_time_spec - initial_time_spec) < uhd::time_spec_t(duration_secs));
-    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
+    usrp->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
 
     //print a summary
     std::cout << std::endl; //go to newline, recv may spew SXSYSZ...
     std::cout << boost::format("    Received packets: %d") % total_recv_packets << std::endl;
     std::cout << boost::format("    Received samples: %d") % total_recv_samples << std::endl;
     std::cout << boost::format("    Lost samples: %d") % total_lost_samples << std::endl;
-    size_t packets_lost = boost::math::iround(double(total_lost_samples)/dev->get_max_recv_samps_per_packet());
+    size_t packets_lost = boost::math::iround(double(total_lost_samples)/max_samps_per_packet);
     std::cout << boost::format("    Lost packets: %d (approximate)") % packets_lost << std::endl;
     double actual_rx_rate_sps = (total_recv_samples*rx_rate_sps)/(total_recv_samples+total_lost_samples);
     std::cout << boost::format("    Sustained receive rate: %f Msps") % (actual_rx_rate_sps/1e6) << std::endl;
@@ -136,22 +137,22 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     if (not vm.count("rate")){
-        sdev->set_rx_rate(500e3); //initial rate
+        usrp->set_rx_rate(500e3); //initial rate
         while(true){
-            double rate = sdev->get_rx_rate();
-            test_device(sdev, rate, duration);
-            sdev->set_rx_rate(rate*2); //double the rate
-            if (sdev->get_rx_rate() == rate) break;
+            double rate = usrp->get_rx_rate();
+            test_device(usrp, rate, duration);
+            usrp->set_rx_rate(rate*2); //double the rate
+            if (usrp->get_rx_rate() == rate) break;
         }
     }
     else{
-        sdev->set_rx_rate(only_rate);
-        double rate = sdev->get_rx_rate();
-        test_device(sdev, rate, duration);
+        usrp->set_rx_rate(only_rate);
+        double rate = usrp->get_rx_rate();
+        test_device(usrp, rate, duration);
     }
 
     //finished
diff --git a/host/examples/rx_ascii_art_dft.cpp b/host/examples/rx_ascii_art_dft.cpp
index 260feca24..c407ecf91 100644
--- a/host/examples/rx_ascii_art_dft.cpp
+++ b/host/examples/rx_ascii_art_dft.cpp
@@ -17,10 +17,10 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include "ascii_art_dft.hpp" //implementation
 #include <boost/program_options.hpp>
-#include <boost/thread.hpp> //gets time
+#include <boost/thread/thread.hpp> //gets time
 #include <boost/format.hpp>
 #include <curses.h>
 #include <iostream>
@@ -41,7 +41,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     po::options_description desc("Allowed options");
     desc.add_options()
         ("help", "help message")
-        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        ("args", po::value<std::string>(&args)->default_value(""), "multi uhd device address args")
         // hardware parameters
         ("rate", po::value<double>(&rate), "rate of incoming samples (sps)")
         ("freq", po::value<double>(&freq)->default_value(0), "RF center frequency in Hz")
@@ -65,23 +65,23 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the rx sample rate
     std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_rx_rate(rate);
-    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate()/1e6) << std::endl << std::endl;
 
     //set the rx center frequency
     std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
-    sdev->set_rx_freq(freq);
-    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+    usrp->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (usrp->get_rx_freq()/1e6) << std::endl << std::endl;
 
     //set the rx rf gain
     std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
-    sdev->set_rx_gain(gain);
-    std::cout << boost::format("Actual RX Gain: %f dB...") % sdev->get_rx_gain() << std::endl << std::endl;
+    usrp->set_rx_gain(gain);
+    std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain() << std::endl << std::endl;
 
     //allocate recv buffer and metatdata
     uhd::rx_metadata_t md;
@@ -90,7 +90,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //-- Initialize
     //------------------------------------------------------------------
     initscr(); //curses init
-    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
+    usrp->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_START_CONTINUOUS);
     boost::system_time next_refresh = boost::get_system_time();
 
     //------------------------------------------------------------------
@@ -98,7 +98,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //------------------------------------------------------------------
     while (true){
         //read a buffer's worth of samples every iteration
-        size_t num_rx_samps = sdev->get_device()->recv(
+        size_t num_rx_samps = usrp->get_device()->recv(
             &buff.front(), buff.size(), md,
             uhd::io_type_t::COMPLEX_FLOAT32,
             uhd::device::RECV_MODE_FULL_BUFF
@@ -115,8 +115,8 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         );
         std::string frame = acsii_art_dft::dft_to_plot(
             lpdft, COLS, LINES,
-            sdev->get_rx_rate(),
-            sdev->get_rx_freq(),
+            usrp->get_rx_rate(),
+            usrp->get_rx_freq(),
             dyn_rng, ref_lvl
         );
 
@@ -133,7 +133,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //------------------------------------------------------------------
     //-- Cleanup
     //------------------------------------------------------------------
-    sdev->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
+    usrp->issue_stream_cmd(uhd::stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS);
     endwin(); //curses done
 
     //finished
diff --git a/host/examples/rx_samples_to_file.cpp b/host/examples/rx_samples_to_file.cpp
index 81977035e..296f480b0 100644
--- a/host/examples/rx_samples_to_file.cpp
+++ b/host/examples/rx_samples_to_file.cpp
@@ -17,7 +17,7 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <boost/program_options.hpp>
 #include <boost/format.hpp>
 #include <boost/thread.hpp>
@@ -39,7 +39,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     po::options_description desc("Allowed options");
     desc.add_options()
         ("help", "help message")
-        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        ("args", po::value<std::string>(&args)->default_value(""), "multi uhd device address args")
         ("file", po::value<std::string>(&file)->default_value("out.16sc.dat"), "name of the file to write binary samples to")
         ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to receive")
         ("rate", po::value<double>(&rate)->default_value(100e6/16), "rate of incoming samples")
@@ -52,49 +52,48 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
 
     //print the help message
     if (vm.count("help")){
-        std::cout << boost::format("UHD RX to File %s") % desc << std::endl;
+        std::cout << boost::format("UHD RX samples to file %s") % desc << std::endl;
         return ~0;
     }
 
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the rx sample rate
     std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_rx_rate(rate);
-    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate()/1e6) << std::endl << std::endl;
 
     //set the rx center frequency
     std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
-    sdev->set_rx_freq(freq);
-    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+    usrp->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (usrp->get_rx_freq()/1e6) << std::endl << std::endl;
 
     //set the rx rf gain
     std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
-    sdev->set_rx_gain(gain);
-    std::cout << boost::format("Actual RX Gain: %f dB...") % sdev->get_rx_gain() << std::endl << std::endl;
+    usrp->set_rx_gain(gain);
+    std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain() << std::endl << std::endl;
 
     boost::this_thread::sleep(boost::posix_time::seconds(1)); //allow for some setup time
-    std::cout << "LO Locked = " << sdev->get_rx_lo_locked() << std::endl;
+    std::cout << "LO Locked = " << usrp->get_rx_lo_locked() << std::endl;
 
     //setup streaming
     uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
     stream_cmd.num_samps = total_num_samps;
     stream_cmd.stream_now = true;
-    sdev->issue_stream_cmd(stream_cmd);
+    usrp->issue_stream_cmd(stream_cmd);
 
     //loop until total number of samples reached
     size_t num_acc_samps = 0; //number of accumulated samples
     uhd::rx_metadata_t md;
-    std::vector<std::complex<short> > buff(dev->get_max_recv_samps_per_packet());
+    std::vector<std::complex<short> > buff(usrp->get_device()->get_max_recv_samps_per_packet());
     std::ofstream outfile(file.c_str(), std::ofstream::binary);
 
     while(num_acc_samps < total_num_samps){
-        size_t num_rx_samps = dev->recv(
+        size_t num_rx_samps = usrp->get_device()->recv(
             &buff.front(), buff.size(), md,
             uhd::io_type_t::COMPLEX_INT16,
             uhd::device::RECV_MODE_ONE_PACKET
diff --git a/host/examples/rx_samples_to_udp.cpp b/host/examples/rx_samples_to_udp.cpp
index 55b9a50ba..801d8e361 100644
--- a/host/examples/rx_samples_to_udp.cpp
+++ b/host/examples/rx_samples_to_udp.cpp
@@ -17,7 +17,7 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <uhd/transport/udp_simple.hpp>
 #include <boost/program_options.hpp>
 #include <boost/format.hpp>
@@ -40,7 +40,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     po::options_description desc("Allowed options");
     desc.add_options()
         ("help", "help message")
-        ("args", po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        ("args", po::value<std::string>(&args)->default_value(""), "multi uhd device address args")
         ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to receive")
         ("rate", po::value<double>(&rate)->default_value(100e6/16), "rate of incoming samples")
         ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
@@ -61,42 +61,41 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the rx sample rate
     std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_rx_rate(rate);
-    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate()/1e6) << std::endl << std::endl;
 
     //set the rx center frequency
     std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
-    sdev->set_rx_freq(freq);
-    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+    usrp->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (usrp->get_rx_freq()/1e6) << std::endl << std::endl;
 
     //set the rx rf gain
     std::cout << boost::format("Setting RX Gain: %f dB...") % gain << std::endl;
-    sdev->set_rx_gain(gain);
-    std::cout << boost::format("Actual RX Gain: %f dB...") % sdev->get_rx_gain() << std::endl << std::endl;
+    usrp->set_rx_gain(gain);
+    std::cout << boost::format("Actual RX Gain: %f dB...") % usrp->get_rx_gain() << std::endl << std::endl;
 
     boost::this_thread::sleep(boost::posix_time::seconds(1)); //allow for some setup time
-    std::cout << "LO Locked = " << sdev->get_rx_lo_locked() << std::endl;
+    std::cout << "LO Locked = " << usrp->get_rx_lo_locked() << std::endl;
 
     //setup streaming
     uhd::stream_cmd_t stream_cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
     stream_cmd.num_samps = total_num_samps;
     stream_cmd.stream_now = true;
-    sdev->issue_stream_cmd(stream_cmd);
+    usrp->issue_stream_cmd(stream_cmd);
 
     //loop until total number of samples reached
     size_t num_acc_samps = 0; //number of accumulated samples
     uhd::rx_metadata_t md;
-    std::vector<std::complex<float> > buff(dev->get_max_recv_samps_per_packet());
+    std::vector<std::complex<float> > buff(usrp->get_device()->get_max_recv_samps_per_packet());
     uhd::transport::udp_simple::sptr udp_xport = uhd::transport::udp_simple::make_connected(addr, port);
 
     while(num_acc_samps < total_num_samps){
-        size_t num_rx_samps = dev->recv(
+        size_t num_rx_samps = usrp->get_device()->recv(
             &buff.front(), buff.size(), md,
             uhd::io_type_t::COMPLEX_FLOAT32,
             uhd::device::RECV_MODE_ONE_PACKET
diff --git a/host/examples/rx_timed_samples.cpp b/host/examples/rx_timed_samples.cpp
index a19532f50..9ebe36c5a 100644
--- a/host/examples/rx_timed_samples.cpp
+++ b/host/examples/rx_timed_samples.cpp
@@ -17,7 +17,7 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <boost/program_options.hpp>
 #include <boost/format.hpp>
 #include <iostream>
@@ -60,22 +60,21 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the rx sample rate
     std::cout << boost::format("Setting RX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_rx_rate(rate);
-    std::cout << boost::format("Actual RX Rate: %f Msps...") % (sdev->get_rx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_rx_rate(rate);
+    std::cout << boost::format("Actual RX Rate: %f Msps...") % (usrp->get_rx_rate()/1e6) << std::endl << std::endl;
 
     //set the rx center frequency
     std::cout << boost::format("Setting RX Freq: %f Mhz...") % (freq/1e6) << std::endl;
-    sdev->set_rx_freq(freq);
-    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (sdev->get_rx_freq()/1e6) << std::endl << std::endl;
+    usrp->set_rx_freq(freq);
+    std::cout << boost::format("Actual RX Freq: %f Mhz...") % (usrp->get_rx_freq()/1e6) << std::endl << std::endl;
 
     std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
-    sdev->set_time_now(uhd::time_spec_t(0.0));
+    usrp->set_time_now(uhd::time_spec_t(0.0));
 
     //setup streaming
     std::cout << std::endl;
@@ -86,14 +85,16 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     stream_cmd.num_samps = total_num_samps;
     stream_cmd.stream_now = false;
     stream_cmd.time_spec = uhd::time_spec_t(seconds_in_future);
-    sdev->issue_stream_cmd(stream_cmd);
+    usrp->issue_stream_cmd(stream_cmd);
+
+    //allocate buffer to receive
+    std::vector<std::complex<float> > buff(usrp->get_device()->get_max_recv_samps_per_packet());
 
     //loop until total number of samples reached
     size_t num_acc_samps = 0; //number of accumulated samples
     while(num_acc_samps < total_num_samps){
         uhd::rx_metadata_t md;
-        std::vector<std::complex<float> > buff(dev->get_max_recv_samps_per_packet());
-        size_t num_rx_samps = dev->recv(
+        size_t num_rx_samps = usrp->get_device()->recv(
             &buff.front(), buff.size(), md,
             uhd::io_type_t::COMPLEX_FLOAT32,
             uhd::device::RECV_MODE_ONE_PACKET
diff --git a/host/examples/test_async_messages.cpp b/host/examples/test_async_messages.cpp
index b1d9d56d4..7f1094ee0 100644
--- a/host/examples/test_async_messages.cpp
+++ b/host/examples/test_async_messages.cpp
@@ -18,7 +18,7 @@
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
 #include <uhd/utils/static.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <boost/assign/list_of.hpp>
 #include <boost/program_options.hpp>
 #include <boost/foreach.hpp>
@@ -35,8 +35,7 @@ namespace po = boost::program_options;
  *    Send a burst of many samples that will fragment internally.
  *    We expect to get an burst ack async message.
  */
-bool test_burst_ack_message(uhd::usrp::single_usrp::sptr sdev){
-    uhd::device::sptr dev = sdev->get_device();
+bool test_burst_ack_message(uhd::usrp::multi_usrp::sptr usrp){
     std::cout << "Test burst ack message... " << std::flush;
 
     uhd::tx_metadata_t md;
@@ -45,16 +44,16 @@ bool test_burst_ack_message(uhd::usrp::single_usrp::sptr sdev){
     md.has_time_spec  = false;
 
     //3 times max-sps guarantees a SOB, no burst, and EOB packet
-    std::vector<std::complex<float> > buff(dev->get_max_send_samps_per_packet()*3);
+    std::vector<std::complex<float> > buff(usrp->get_device()->get_max_send_samps_per_packet()*3);
 
-    dev->send(
+    usrp->get_device()->send(
         &buff.front(), buff.size(), md,
         uhd::io_type_t::COMPLEX_FLOAT32,
         uhd::device::SEND_MODE_FULL_BUFF
     );
 
     uhd::async_metadata_t async_md;
-    if (not dev->recv_async_msg(async_md)){
+    if (not usrp->get_device()->recv_async_msg(async_md)){
         std::cout << boost::format(
             "failed:\n"
             "    Async message recv timed out.\n"
@@ -84,8 +83,7 @@ bool test_burst_ack_message(uhd::usrp::single_usrp::sptr sdev){
  *    Send a start of burst packet with no following end of burst.
  *    We expect to get an underflow(within a burst) async message.
  */
-bool test_underflow_message(uhd::usrp::single_usrp::sptr sdev){
-    uhd::device::sptr dev = sdev->get_device();
+bool test_underflow_message(uhd::usrp::multi_usrp::sptr usrp){
     std::cout << "Test underflow message... " << std::flush;
 
     uhd::tx_metadata_t md;
@@ -93,14 +91,14 @@ bool test_underflow_message(uhd::usrp::single_usrp::sptr sdev){
     md.end_of_burst   = false;
     md.has_time_spec  = false;
 
-    dev->send(
+    usrp->get_device()->send(
         NULL, 0, md,
         uhd::io_type_t::COMPLEX_FLOAT32,
         uhd::device::SEND_MODE_FULL_BUFF
     );
 
     uhd::async_metadata_t async_md;
-    if (not dev->recv_async_msg(async_md, 1)){
+    if (not usrp->get_device()->recv_async_msg(async_md, 1)){
         std::cout << boost::format(
             "failed:\n"
             "    Async message recv timed out.\n"
@@ -130,8 +128,7 @@ bool test_underflow_message(uhd::usrp::single_usrp::sptr sdev){
  *    Send a burst packet that occurs at a time in the past.
  *    We expect to get a time error async message.
  */
-bool test_time_error_message(uhd::usrp::single_usrp::sptr sdev){
-    uhd::device::sptr dev = sdev->get_device();
+bool test_time_error_message(uhd::usrp::multi_usrp::sptr usrp){
     std::cout << "Test time error message... " << std::flush;
 
     uhd::tx_metadata_t md;
@@ -140,16 +137,16 @@ bool test_time_error_message(uhd::usrp::single_usrp::sptr sdev){
     md.has_time_spec  = true;
     md.time_spec      = uhd::time_spec_t(100.0); //send at 100s
 
-    sdev->set_time_now(uhd::time_spec_t(200.0)); //time at 200s
+    usrp->set_time_now(uhd::time_spec_t(200.0)); //time at 200s
 
-    dev->send(
+    usrp->get_device()->send(
         NULL, 0, md,
         uhd::io_type_t::COMPLEX_FLOAT32,
         uhd::device::SEND_MODE_FULL_BUFF
     );
 
     uhd::async_metadata_t async_md;
-    if (not dev->recv_async_msg(async_md)){
+    if (not usrp->get_device()->recv_async_msg(async_md)){
         std::cout << boost::format(
             "failed:\n"
             "    Async message recv timed out.\n"
@@ -174,10 +171,9 @@ bool test_time_error_message(uhd::usrp::single_usrp::sptr sdev){
     }
 }
 
-void flush_async_md(uhd::usrp::single_usrp::sptr sdev){
-    uhd::device::sptr dev = sdev->get_device();
+void flush_async_md(uhd::usrp::multi_usrp::sptr usrp){
     uhd::async_metadata_t async_md;
-    while (dev->recv_async_msg(async_md, 1.0)){}
+    while (usrp->get_device()->recv_async_msg(async_md, 1.0)){}
 }
 
 int UHD_SAFE_MAIN(int argc, char *argv[]){
@@ -192,7 +188,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     po::options_description desc("Allowed options");
     desc.add_options()
         ("help", "help message")
-        ("args",   po::value<std::string>(&args)->default_value(""), "single uhd device address args")
+        ("args",   po::value<std::string>(&args)->default_value(""), "multi uhd device address args")
         ("rate",   po::value<double>(&rate)->default_value(1.5e6),   "rate of outgoing samples")
         ("ntests", po::value<size_t>(&ntests)->default_value(10),    "number of tests to run")
     ;
@@ -209,18 +205,18 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the tx sample rate
     std::cout << boost::format("Setting TX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_tx_rate(rate);
-    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_tx_rate(rate);
+    std::cout << boost::format("Actual TX Rate: %f Msps...") % (usrp->get_tx_rate()/1e6) << std::endl << std::endl;
 
     //------------------------------------------------------------------
     // begin asyc messages test
     //------------------------------------------------------------------
-    static const uhd::dict<std::string, boost::function<bool(uhd::usrp::single_usrp::sptr)> >
+    static const uhd::dict<std::string, boost::function<bool(uhd::usrp::multi_usrp::sptr)> >
         tests = boost::assign::map_list_of
         ("Test Burst ACK ", &test_burst_ack_message)
         ("Test Underflow ", &test_underflow_message)
@@ -237,8 +233,8 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //run the tests, pick at random
     for (size_t n = 0; n < ntests; n++){
         std::string key = tests.keys()[std::rand() % tests.size()];
-        bool pass = tests[key](sdev);
-        flush_async_md(sdev);
+        bool pass = tests[key](usrp);
+        flush_async_md(usrp);
 
         //store result
         if (pass) successes[key]++;
diff --git a/host/examples/test_pps_input.cpp b/host/examples/test_pps_input.cpp
index 273c73df0..994b7ca87 100644
--- a/host/examples/test_pps_input.cpp
+++ b/host/examples/test_pps_input.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright 2010 Ettus Research LLC
+// Copyright 2010-2011 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -51,13 +51,12 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::multi_usrp::sptr sdev = uhd::usrp::multi_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the time at an unknown pps (will throw if no pps)
     std::cout << std::endl << "Attempt to detect the PPS and set the time..." << std::endl << std::endl;
-    sdev->set_time_unknown_pps(uhd::time_spec_t(0.0));
+    usrp->set_time_unknown_pps(uhd::time_spec_t(0.0));
     std::cout << std::endl << "Success!" << std::endl << std::endl;
     return 0;
 }
diff --git a/host/examples/tx_from_file.cpp b/host/examples/tx_from_file.cpp
deleted file mode 100644
index 8af9b0f4a..000000000
--- a/host/examples/tx_from_file.cpp
+++ /dev/null
@@ -1,124 +0,0 @@
-//
-// Copyright 2010-2011 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include <uhd/utils/thread_priority.hpp>
-#include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/simple_usrp.hpp>
-#include <boost/program_options.hpp>
-#include <boost/format.hpp>
-#include <iostream>
-#include <complex>
-#include <fstream>
-
-namespace po = boost::program_options;
-
-int UHD_SAFE_MAIN(int argc, char *argv[]){
-    uhd::set_thread_priority_safe();
-
-    //variables to be set by po
-    std::string args;
-    double seconds_in_future;
-    size_t total_num_samps;
-    size_t samps_per_packet;
-    double tx_rate, freq, gain;
-    float ampl;
-
-    //setup the program options
-    po::options_description desc("Allowed options");
-    desc.add_options()
-        ("help", "help message")
-        ("args", po::value<std::string>(&args)->default_value(""), "simple uhd device address args")
-        ("secs", po::value<double>(&seconds_in_future)->default_value(3), "number of seconds in the future to transmit")
-        ("nsamps", po::value<size_t>(&total_num_samps)->default_value(1000), "total number of samples to transmit")
-        ("txrate", po::value<double>(&tx_rate)->default_value(100e6/16), "rate of outgoing samples")
-        ("freq", po::value<double>(&freq)->default_value(0), "rf center frequency in Hz")
-        ("ampl", po::value<float>(&ampl)->default_value(float(0.3)), "amplitude of each sample")
-        ("gain", po::value<double>(&gain)->default_value(0), "amplitude of each sample")
-        ("dilv", "specify to disable inner-loop verbose")
-    ;
-    po::variables_map vm;
-    po::store(po::parse_command_line(argc, argv, desc), vm);
-    po::notify(vm);
-
-    //print the help message
-    if (vm.count("help")){
-        std::cout << boost::format("UHD TX Timed Samples %s") % desc << std::endl;
-        return ~0;
-    }
-
-    bool verbose = vm.count("dilv") == 0;
-
-    //create a usrp device
-    std::cout << std::endl;
-    std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::simple_usrp::sptr sdev = uhd::usrp::simple_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
-
-    //set properties on the device
-    std::cout << boost::format("Setting TX Rate: %f Msps...") % (tx_rate/1e6) << std::endl;
-    sdev->set_tx_rate(tx_rate);
-    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl;
-    std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
-    sdev->set_tx_freq(freq);
-    sdev->set_time_now(uhd::time_spec_t(0.0));
-
-    sdev->set_gain(gain);
-
-    //allocate data to send
-    std::vector<std::complex<short> > buff;
-    uhd::tx_metadata_t md;
-
-    std::cout << "Read data to send from file: in.dat" << std::endl;
-    std::ifstream infile("in.dat", std::ifstream::binary);
-    while (!infile.eof()) {
-        std::complex<short> c;
-        infile.read((char *)&c, sizeof(std::complex<short>));
-        if (!((c.real() == 0) && (c.imag() == 0))) {
-            buff.push_back(c); 
-//std::cout << "C = " << c << std::endl;
-        }
-    }
-    samps_per_packet = buff.size();
-    infile.close();
-    std::cout << "Number of samples in file: " << samps_per_packet << std::endl;
-
-    //send the data in multiple packets
-    size_t num_packets = (total_num_samps+samps_per_packet-1)/samps_per_packet;
-    for (size_t i = 0; i < num_packets; i++){
-        //setup the metadata flags and time spec
-        md.start_of_burst = (i == 0);              //only first packet has SOB
-        md.end_of_burst   = (i == num_packets-1);  //only last packet has EOB
-        md.has_time_spec  = (i == 0);              //only first packet has time
-        md.time_spec = uhd::time_spec_t(seconds_in_future);
-
-        size_t samps_to_send = std::min(total_num_samps - samps_per_packet*i, samps_per_packet);
-
-        //send the entire packet (driver fragments internally)
-        size_t num_tx_samps = dev->send(
-            &buff.front(), samps_to_send, md,
-            uhd::io_type_t::COMPLEX_INT16,
-            uhd::device::SEND_MODE_FULL_BUFF
-        );
-        if(verbose) std::cout << std::endl << boost::format("Sent %d samples") % num_tx_samps << std::endl;
-    }
-
-    //finished
-    std::cout << std::endl << "Done!" << std::endl << std::endl;
-
-    return 0;
-}
diff --git a/host/examples/tx_timed_samples.cpp b/host/examples/tx_timed_samples.cpp
index 6d6aa7010..f10d7e4ea 100644
--- a/host/examples/tx_timed_samples.cpp
+++ b/host/examples/tx_timed_samples.cpp
@@ -17,8 +17,9 @@
 
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <boost/program_options.hpp>
+#include <boost/thread/thread.hpp>
 #include <boost/format.hpp>
 #include <iostream>
 #include <complex>
@@ -64,22 +65,21 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the tx sample rate
     std::cout << boost::format("Setting TX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_tx_rate(rate);
-    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_tx_rate(rate);
+    std::cout << boost::format("Actual TX Rate: %f Msps...") % (usrp->get_tx_rate()/1e6) << std::endl << std::endl;
 
     //set the tx center frequency
     std::cout << boost::format("Setting TX Freq: %f Mhz...") % (freq/1e6) << std::endl;
-    sdev->set_tx_freq(freq);
-    std::cout << boost::format("Actual TX Freq: %f Mhz...") % (sdev->get_tx_freq()/1e6) << std::endl << std::endl;
+    usrp->set_tx_freq(freq);
+    std::cout << boost::format("Actual TX Freq: %f Mhz...") % (usrp->get_tx_freq()/1e6) << std::endl << std::endl;
 
     std::cout << boost::format("Setting device timestamp to 0...") << std::endl;
-    sdev->set_time_now(uhd::time_spec_t(0.0));
+    usrp->set_time_now(uhd::time_spec_t(0.0));
 
     //allocate data to send
     std::vector<std::complex<float> > buff(samps_per_packet, std::complex<float>(ampl, ampl));
@@ -99,7 +99,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         size_t samps_to_send = std::min(total_num_samps - samps_per_packet*i, samps_per_packet);
 
         //send the entire packet (driver fragments internally)
-        size_t num_tx_samps = dev->send(
+        size_t num_tx_samps = usrp->get_device()->send(
             &buff.front(), samps_to_send, md,
             uhd::io_type_t::COMPLEX_FLOAT32,
             uhd::device::SEND_MODE_FULL_BUFF,
@@ -110,6 +110,9 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         if(verbose) std::cout << std::endl << boost::format("Sent %d samples") % num_tx_samps << std::endl;
     }
 
+    //ensure that the buffers have flushed out to the device before deconstruction
+    boost::this_thread::sleep(boost::posix_time::seconds(1));
+
     //finished
     std::cout << std::endl << "Done!" << std::endl << std::endl;
 
diff --git a/host/examples/tx_waveforms.cpp b/host/examples/tx_waveforms.cpp
index 553d6739d..dd18d3174 100644
--- a/host/examples/tx_waveforms.cpp
+++ b/host/examples/tx_waveforms.cpp
@@ -18,7 +18,7 @@
 #include <uhd/utils/thread_priority.hpp>
 #include <uhd/utils/safe_main.hpp>
 #include <uhd/utils/static.hpp>
-#include <uhd/usrp/single_usrp.hpp>
+#include <uhd/usrp/multi_usrp.hpp>
 #include <boost/program_options.hpp>
 #include <boost/thread/thread_time.hpp> //system time
 #include <boost/math/special_functions/round.hpp>
@@ -93,35 +93,34 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //create a usrp device
     std::cout << std::endl;
     std::cout << boost::format("Creating the usrp device with: %s...") % args << std::endl;
-    uhd::usrp::single_usrp::sptr sdev = uhd::usrp::single_usrp::make(args);
-    uhd::device::sptr dev = sdev->get_device();
-    std::cout << boost::format("Using Device: %s") % sdev->get_pp_string() << std::endl;
+    uhd::usrp::multi_usrp::sptr usrp = uhd::usrp::multi_usrp::make(args);
+    std::cout << boost::format("Using Device: %s") % usrp->get_pp_string() << std::endl;
 
     //set the tx sample rate
     std::cout << boost::format("Setting TX Rate: %f Msps...") % (rate/1e6) << std::endl;
-    sdev->set_tx_rate(rate);
-    std::cout << boost::format("Actual TX Rate: %f Msps...") % (sdev->get_tx_rate()/1e6) << std::endl << std::endl;
+    usrp->set_tx_rate(rate);
+    std::cout << boost::format("Actual TX Rate: %f Msps...") % (usrp->get_tx_rate()/1e6) << std::endl << std::endl;
 
     //set the tx center frequency
     std::cout << boost::format("Setting TX Freq: %f Mhz...") % (freq/1e6) << std::endl;
-    sdev->set_tx_freq(freq);
-    std::cout << boost::format("Actual TX Freq: %f Mhz...") % (sdev->get_tx_freq()/1e6) << std::endl << std::endl;
+    usrp->set_tx_freq(freq);
+    std::cout << boost::format("Actual TX Freq: %f Mhz...") % (usrp->get_tx_freq()/1e6) << std::endl << std::endl;
 
     //set the tx rf gain
     std::cout << boost::format("Setting TX Gain: %f dB...") % gain << std::endl;
-    sdev->set_tx_gain(gain);
-    std::cout << boost::format("Actual TX Gain: %f dB...") % sdev->get_tx_gain() << std::endl << std::endl;
+    usrp->set_tx_gain(gain);
+    std::cout << boost::format("Actual TX Gain: %f dB...") % usrp->get_tx_gain() << std::endl << std::endl;
 
     //for the const wave, set the wave freq for small samples per period
     if (wave_freq == 0 and wave_type == "CONST"){
-        wave_freq = sdev->get_tx_rate()/2;
+        wave_freq = usrp->get_tx_rate()/2;
     }
 
     //error when the waveform is not possible to generate
-    if (std::abs(wave_freq) > sdev->get_tx_rate()/2){
+    if (std::abs(wave_freq) > usrp->get_tx_rate()/2){
         throw std::runtime_error("wave freq out of Nyquist zone");
     }
-    if (sdev->get_tx_rate()/std::abs(wave_freq) > sine_table_len/2 and wave_type == "SINE"){
+    if (usrp->get_tx_rate()/std::abs(wave_freq) > sine_table_len/2 and wave_type == "SINE"){
         throw std::runtime_error("sine freq too small for table");
     }
 
@@ -135,7 +134,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
 
     //allocate the buffer and precalculate values
     std::vector<std::complex<float> > buff(spb);
-    const float cps = float(wave_freq/sdev->get_tx_rate());
+    const float cps = float(wave_freq/usrp->get_tx_rate());
     const float i_off = (wave_freq > 0)? float(0.25) : 0;
     const float q_off = (wave_freq < 0)? float(0.25) : 0;
     float theta = 0;
@@ -162,7 +161,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
         theta = std::fmod(theta, 1);
 
         //send the entire contents of the buffer
-        dev->send(
+        usrp->get_device()->send(
             &buff.front(), buff.size(), md,
             uhd::io_type_t::COMPLEX_FLOAT32,
             uhd::device::SEND_MODE_FULL_BUFF
@@ -172,7 +171,7 @@ int UHD_SAFE_MAIN(int argc, char *argv[]){
     //send a mini EOB packet
     md.start_of_burst = false;
     md.end_of_burst   = true;
-    dev->send(NULL, 0, md,
+    usrp->get_device()->send(NULL, 0, md,
         uhd::io_type_t::COMPLEX_FLOAT32,
         uhd::device::SEND_MODE_FULL_BUFF
     );
diff --git a/host/include/uhd/transport/bounded_buffer.ipp b/host/include/uhd/transport/bounded_buffer.ipp
index f7915d866..4fbe3f085 100644
--- a/host/include/uhd/transport/bounded_buffer.ipp
+++ b/host/include/uhd/transport/bounded_buffer.ipp
@@ -22,6 +22,7 @@
 #include <boost/function.hpp>
 #include <boost/circular_buffer.hpp>
 #include <boost/thread/condition.hpp>
+#include <boost/thread/locks.hpp>
 #include <boost/date_time/posix_time/posix_time_types.hpp>
 
 namespace uhd{ namespace transport{ namespace{ /*anon*/
@@ -36,7 +37,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE bool push_with_pop_on_full(const elem_type &elem){
-            boost::unique_lock<boost::mutex> lock(_mutex);
+            boost::mutex::scoped_lock lock(_mutex);
             if(_buffer.full()){
                 _buffer.pop_back();
                 _buffer.push_front(elem);
@@ -53,7 +54,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE void push_with_wait(const elem_type &elem){
-            boost::unique_lock<boost::mutex> lock(_mutex);
+            boost::mutex::scoped_lock lock(_mutex);
             _full_cond.wait(lock, _not_full_fcn);
             _buffer.push_front(elem);
             lock.unlock();
@@ -61,7 +62,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE bool push_with_timed_wait(const elem_type &elem, double timeout){
-            boost::unique_lock<boost::mutex> lock(_mutex);
+            boost::mutex::scoped_lock lock(_mutex);
             if (not _full_cond.timed_wait(
                 lock, to_time_dur(timeout), _not_full_fcn
             )) return false;
@@ -72,7 +73,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE void pop_with_wait(elem_type &elem){
-            boost::unique_lock<boost::mutex> lock(_mutex);
+            boost::mutex::scoped_lock lock(_mutex);
             _empty_cond.wait(lock, _not_empty_fcn);
             elem = this->pop_back();
             lock.unlock();
@@ -80,7 +81,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE bool pop_with_timed_wait(elem_type &elem, double timeout){
-            boost::unique_lock<boost::mutex> lock(_mutex);
+            boost::mutex::scoped_lock lock(_mutex);
             if (not _empty_cond.timed_wait(
                 lock, to_time_dur(timeout), _not_empty_fcn
             )) return false;
@@ -91,7 +92,7 @@ namespace uhd{ namespace transport{ namespace{ /*anon*/
         }
 
         UHD_INLINE void clear(void){
-            boost::unique_lock<boost::mutex> lock(_mutex);
+            boost::mutex::scoped_lock lock(_mutex);
             while (not_empty()) this->pop_back();
             lock.unlock();
             _full_cond.notify_one();
diff --git a/host/include/uhd/types/io_type.hpp b/host/include/uhd/types/io_type.hpp
index 5176374d6..ec1b9c056 100644
--- a/host/include/uhd/types/io_type.hpp
+++ b/host/include/uhd/types/io_type.hpp
@@ -1,5 +1,5 @@
 //
-// Copyright 2010 Ettus Research LLC
+// Copyright 2010-2011 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -33,9 +33,13 @@ namespace uhd{
          * Built in IO types known to the system.
          */
         enum tid_t{
+            //! Custom type (technically unsupported by implementation)
             CUSTOM_TYPE =     '?',
+            //! Complex floating point (32-bit floats) range [-1.0, +1.0]
             COMPLEX_FLOAT32 = 'f',
+            //! Complex signed integer (16-bit integers) range [-32768, +32767]
             COMPLEX_INT16 =   's',
+            //! Complex signed integer (8-bit integers) range [-128, 127]
             COMPLEX_INT8 =    'b'
         };
 
diff --git a/host/include/uhd/usrp/dboard_iface.hpp b/host/include/uhd/usrp/dboard_iface.hpp
index cfb727017..c5898365d 100644
--- a/host/include/uhd/usrp/dboard_iface.hpp
+++ b/host/include/uhd/usrp/dboard_iface.hpp
@@ -28,6 +28,27 @@
 
 namespace uhd{ namespace usrp{
 
+//! Special properties that differentiate this daughterboard slot
+struct UHD_API dboard_iface_special_props_t{
+    /*!
+     * Soft clock divider:
+     * When a motherboard cannot provided a divided dboard clock,
+     * it may provided a "soft" divided clock over an FPGA GPIO.
+     * The implementation must know the type of clock provided.
+     */
+    bool soft_clock_divider;
+
+    /*!
+     * Mangle i2c addresses:
+     * When i2c is shared across multiple daugterboard slots,
+     * the i2c addresses will be mangled on the secondary slot
+     * to avoid conflicts between slots in the i2c address space.
+     * The mangling is daguhterboard specific so the implementation
+     * needs to know whether it should use mangled addresses or not.
+     */
+    bool mangle_i2c_addrs;
+};
+
 /*!
  * The daughter board dboard interface to be subclassed.
  * A dboard instance interfaces with the mboard though this api.
@@ -37,6 +58,7 @@ namespace uhd{ namespace usrp{
 class UHD_API dboard_iface{
 public:
     typedef boost::shared_ptr<dboard_iface> sptr;
+    typedef dboard_iface_special_props_t special_props_t;
 
     //! tells the host which unit to use
     enum unit_t{
@@ -66,27 +88,6 @@ public:
         AUX_ADC_B = 'b'
     };
 
-    //! Special properties that differentiate this daughterboard slot
-    struct special_props_t{
-        /*!
-         * Soft clock divider:
-         * When a motherboard cannot provided a divided dboard clock,
-         * it may provided a "soft" divided clock over an FPGA GPIO.
-         * The implementation must know the type of clock provided.
-         */
-        bool soft_clock_divider;
-
-        /*!
-         * Mangle i2c addresses:
-         * When i2c is shared across multiple daugterboard slots,
-         * the i2c addresses will be mangled on the secondary slot
-         * to avoid conflicts between slots in the i2c address space.
-         * The mangling is daguhterboard specific so the implementation
-         * needs to know whether it should use mangled addresses or not.
-         */
-        bool mangle_i2c_addrs;
-    };
-
     /*!
      * Get special properties information for this dboard slot.
      * This call helps the dboard code to handle implementation
diff --git a/host/include/uhd/usrp/mboard_props.hpp b/host/include/uhd/usrp/mboard_props.hpp
index c82bfc21a..d04ad012c 100644
--- a/host/include/uhd/usrp/mboard_props.hpp
+++ b/host/include/uhd/usrp/mboard_props.hpp
@@ -31,6 +31,7 @@ namespace uhd{ namespace usrp{
     enum mboard_prop_t{
         MBOARD_PROP_NAME            = 'n', //ro, std::string
         MBOARD_PROP_OTHERS          = 'o', //ro, prop_names_t
+        MBOARD_PROP_CLOCK_RATE      = 'c', //rw, double
         MBOARD_PROP_RX_DSP          = 'd', //ro, wax::obj
         MBOARD_PROP_RX_DSP_NAMES    = 'D', //ro, prop_names_t
         MBOARD_PROP_TX_DSP          = 'u', //ro, wax::obj
diff --git a/host/include/uhd/usrp/multi_usrp.hpp b/host/include/uhd/usrp/multi_usrp.hpp
index b603d4324..c77b5d6d2 100644
--- a/host/include/uhd/usrp/multi_usrp.hpp
+++ b/host/include/uhd/usrp/multi_usrp.hpp
@@ -34,19 +34,30 @@
 namespace uhd{ namespace usrp{
 
 /*!
- * The multi-USRP device class:
- * A multi-USRP facilitates ease-of-use for multiple USRP scenarios.
- * The wrapper provides convenience functions to control the group
- * of underlying devices as if they consisted of a single device.
+ * The Multi-USRP device class:
  *
- * A few notes about a multi-USRP configuration:
+ * This class facilitates ease-of-use for most use-case scenarios.
+ * The wrapper provides convenience functions to tune the devices,
+ * set the dboard gains, antennas, filters, and other properties.
+ * This class can be used to interface with a single USRP with
+ * one or more channels, or multiple USRPs in a homogeneous setup.
+ * All members take an optional parameter for board number or channel number.
+ * In the single device, single channel case, these parameters can be unspecified.
+ *
+ * When using a single device with multiple channels:
+ *  - Channel mapping is determined by the subdevice specifications
+ *  - All channels share a common RX sample rate
+ *  - All channels share a common TX sample rate
+ *
+ * When using multiple devices in a configuration:
+ *  - Channel mapping is determined by the device address arguments
  *  - All boards share a common RX sample rate
  *  - All boards share a common TX sample rate
  *  - All boards share a common RX subdevice specification size
  *  - All boards share a common TX subdevice specification size
  *  - All boards must have synchronized times (see the set_time_*() calls)
  *
- * Example to setup channel mapping:
+ * Example to setup channel mapping for multiple devices:
  * <pre>
  *
  * //create a multi_usrp with two boards in the configuration
@@ -95,6 +106,26 @@ public:
     /*******************************************************************
      * Mboard methods
      ******************************************************************/
+
+    /*!
+     * Set the master clock rate.
+     * This controls the rate of the clock that feeds the FPGA DSP.
+     * On some devices, this re-tunes the clock to the specified rate.
+     * If the specified rate is not available, this method will throw.
+     * On other devices, this method notifies the software of the rate,
+     * but requires the the user has made the necessary hardware change.
+     * \param rate the new master clock rate in Hz
+     * \param mboard the motherboard index 0 to M-1
+     */
+    virtual void set_master_clock_rate(double rate, size_t mboard = ALL_MBOARDS) = 0;
+
+    /*!
+     * Get the master clock rate.
+     * \param mboard the motherboard index 0 to M-1
+     * \return the master clock rate in Hz.
+     */
+    virtual double get_master_clock_rate(size_t mboard = 0) = 0;
+
     /*!
      * Get a printable summary for this USRP configuration.
      * \return a printable string
@@ -106,7 +137,7 @@ public:
      * \param mboard which motherboard to query
      * \return a string representing the name
      */
-    virtual std::string get_mboard_name(size_t mboard) = 0;
+    virtual std::string get_mboard_name(size_t mboard = 0) = 0;
 
     /*!
      * Get the current time in the usrp time registers.
@@ -121,6 +152,19 @@ public:
     virtual time_spec_t get_time_last_pps(void) = 0;
 
     /*!
+     * Sets the time registers on the usrp immediately.
+     *
+     * If only one MIMO master is present in your configuration, set_time_now is
+     * safe to use because the slave's time automatically follows the master's time.
+     * Otherwise, this call cannot set the time synchronously across multiple devices.
+     * Please use the set_time_next_pps or set_time_unknown_pps calls with a PPS signal.
+     *
+     * \param time_spec the time to latch into the usrp device
+     * \param mboard the motherboard index 0 to M-1
+     */
+    virtual void set_time_now(const time_spec_t &time_spec, size_t mboard = ALL_MBOARDS) = 0;
+
+    /*!
      * Set the time registers on the usrp at the next pps tick.
      * The values will not be latched in until the pulse occurs.
      * It is recommended that the user sleep(1) after calling to ensure
@@ -162,6 +206,11 @@ public:
      * Issue a stream command to the usrp device.
      * This tells the usrp to send samples into the host.
      * See the documentation for stream_cmd_t for more info.
+     *
+     * With multiple devices, the first stream command in a chain of commands
+     * should have a time spec in the near future and stream_now = false;
+     * to ensure that the packets can be aligned by their time specs.
+     *
      * \param stream_cmd the stream command to issue
      */
     virtual void issue_stream_cmd(const stream_cmd_t &stream_cmd) = 0;
@@ -173,7 +222,7 @@ public:
      * \param clock_config the clock configuration to set
      * \param mboard which motherboard to set the config
      */
-    virtual void set_clock_config(const clock_config_t &clock_config, size_t mboard) = 0;
+    virtual void set_clock_config(const clock_config_t &clock_config, size_t mboard = ALL_MBOARDS) = 0;
 
     /*!
      * Get the number of USRP motherboards in this configuration.
@@ -191,14 +240,14 @@ public:
      * \param spec the new subdevice specification
      * \param mboard the motherboard index 0 to M-1
      */
-    virtual void set_rx_subdev_spec(const uhd::usrp::subdev_spec_t &spec, size_t mboard) = 0;
+    virtual void set_rx_subdev_spec(const uhd::usrp::subdev_spec_t &spec, size_t mboard = ALL_MBOARDS) = 0;
 
     /*!
      * Get the RX subdevice specification.
      * \param mboard the motherboard index 0 to M-1
      * \return the subdevice specification in use
      */
-    virtual uhd::usrp::subdev_spec_t get_rx_subdev_spec(size_t mboard) = 0;
+    virtual uhd::usrp::subdev_spec_t get_rx_subdev_spec(size_t mboard = 0) = 0;
 
     /*!
      * Get the number of RX channels in this configuration.
@@ -212,7 +261,7 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the subdevice name
      */
-    virtual std::string get_rx_subdev_name(size_t chan) = 0;
+    virtual std::string get_rx_subdev_name(size_t chan = 0) = 0;
 
     /*!
      * Set the RX sample rate across all channels.
@@ -241,14 +290,14 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the frequency in Hz
      */
-    virtual double get_rx_freq(size_t chan) = 0;
+    virtual double get_rx_freq(size_t chan = 0) = 0;
 
     /*!
      * Get the RX center frequency range.
      * \param chan the channel index 0 to N-1
      * \return a frequency range object
      */
-    virtual freq_range_t get_rx_freq_range(size_t chan) = 0;
+    virtual freq_range_t get_rx_freq_range(size_t chan = 0) = 0;
 
     /*!
      * Set the RX gain value for the specified gain element.
@@ -257,10 +306,10 @@ public:
      * \param name the name of the gain element
      * \param chan the channel index 0 to N-1
      */
-    virtual void set_rx_gain(double gain, const std::string &name, size_t chan) = 0;
+    virtual void set_rx_gain(double gain, const std::string &name, size_t chan = 0) = 0;
 
     //! A convenience wrapper for setting overall RX gain
-    void set_rx_gain(double gain, size_t chan){
+    void set_rx_gain(double gain, size_t chan = 0){
         return this->set_rx_gain(gain, ALL_GAINS, chan);
     }
 
@@ -271,10 +320,10 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the gain in dB
      */
-    virtual double get_rx_gain(const std::string &name, size_t chan) = 0;
+    virtual double get_rx_gain(const std::string &name, size_t chan = 0) = 0;
 
     //! A convenience wrapper for getting overall RX gain
-    double get_rx_gain(size_t chan){
+    double get_rx_gain(size_t chan = 0){
         return this->get_rx_gain(ALL_GAINS, chan);
     }
 
@@ -285,10 +334,10 @@ public:
      * \param chan the channel index 0 to N-1
      * \return a gain range object
      */
-    virtual gain_range_t get_rx_gain_range(const std::string &name, size_t chan) = 0;
+    virtual gain_range_t get_rx_gain_range(const std::string &name, size_t chan = 0) = 0;
 
     //! A convenience wrapper for getting overall RX gain range
-    gain_range_t get_rx_gain_range(size_t chan){
+    gain_range_t get_rx_gain_range(size_t chan = 0){
         return this->get_rx_gain_range(ALL_GAINS, chan);
     }
 
@@ -298,49 +347,49 @@ public:
      * \param chan the channel index 0 to N-1
      * \return a vector of gain element names
      */
-    virtual std::vector<std::string> get_rx_gain_names(size_t chan) = 0;
+    virtual std::vector<std::string> get_rx_gain_names(size_t chan = 0) = 0;
 
     /*!
      * Select the RX antenna on the subdevice.
      * \param ant the antenna name
      * \param chan the channel index 0 to N-1
      */
-    virtual void set_rx_antenna(const std::string &ant, size_t chan) = 0;
+    virtual void set_rx_antenna(const std::string &ant, size_t chan = 0) = 0;
 
     /*!
      * Get the selected RX antenna on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return the antenna name
      */
-    virtual std::string get_rx_antenna(size_t chan) = 0;
+    virtual std::string get_rx_antenna(size_t chan = 0) = 0;
 
     /*!
      * Get a list of possible RX antennas on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return a vector of antenna names
      */
-    virtual std::vector<std::string> get_rx_antennas(size_t chan) = 0;
+    virtual std::vector<std::string> get_rx_antennas(size_t chan = 0) = 0;
 
     /*!
      * Get the locked status of the LO on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return true for locked
      */
-    virtual bool get_rx_lo_locked(size_t chan) = 0;
+    virtual bool get_rx_lo_locked(size_t chan = 0) = 0;
 
     /*!
      * Set the RX bandwidth on the subdevice.
      * \param bandwidth the bandwidth in Hz
      * \param chan the channel index 0 to N-1
      */
-    virtual void set_rx_bandwidth(double bandwidth, size_t chan) = 0;
+    virtual void set_rx_bandwidth(double bandwidth, size_t chan = 0) = 0;
 
     /*!
      * Get the RX bandwidth on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return the bandwidth in Hz
      */
-    virtual double get_rx_bandwidth(size_t chan) = 0;
+    virtual double get_rx_bandwidth(size_t chan = 0) = 0;
 
     /*!
      * Read the RSSI value on the RX subdevice.
@@ -348,7 +397,7 @@ public:
      * \return the rssi in dB
      * \throw exception if RSSI readback not supported
      */
-    virtual double read_rssi(size_t chan) = 0;
+    virtual double read_rssi(size_t chan = 0) = 0;
 
     /*!
      * Get the dboard interface object for the RX subdevice.
@@ -357,7 +406,7 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the dboard interface sptr
      */
-    virtual dboard_iface::sptr get_rx_dboard_iface(size_t chan) = 0;
+    virtual dboard_iface::sptr get_rx_dboard_iface(size_t chan = 0) = 0;
 
     /*******************************************************************
      * TX methods
@@ -370,14 +419,14 @@ public:
      * \param spec the new subdevice specification
      * \param mboard the motherboard index 0 to M-1
      */
-    virtual void set_tx_subdev_spec(const uhd::usrp::subdev_spec_t &spec, size_t mboard) = 0;
+    virtual void set_tx_subdev_spec(const uhd::usrp::subdev_spec_t &spec, size_t mboard = ALL_MBOARDS) = 0;
 
     /*!
      * Get the TX subdevice specification.
      * \param mboard the motherboard index 0 to M-1
      * \return the subdevice specification in use
      */
-    virtual uhd::usrp::subdev_spec_t get_tx_subdev_spec(size_t mboard) = 0;
+    virtual uhd::usrp::subdev_spec_t get_tx_subdev_spec(size_t mboard = 0) = 0;
 
     /*!
      * Get the number of TX channels in this configuration.
@@ -391,7 +440,7 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the subdevice name
      */
-    virtual std::string get_tx_subdev_name(size_t chan) = 0;
+    virtual std::string get_tx_subdev_name(size_t chan = 0) = 0;
 
     /*!
      * Set the TX sample rate across all channels.
@@ -420,14 +469,14 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the frequency in Hz
      */
-    virtual double get_tx_freq(size_t chan) = 0;
+    virtual double get_tx_freq(size_t chan = 0) = 0;
 
     /*!
      * Get the TX center frequency range.
      * \param chan the channel index 0 to N-1
      * \return a frequency range object
      */
-    virtual freq_range_t get_tx_freq_range(size_t chan) = 0;
+    virtual freq_range_t get_tx_freq_range(size_t chan = 0) = 0;
 
     /*!
      * Set the TX gain value for the specified gain element.
@@ -436,10 +485,10 @@ public:
      * \param name the name of the gain element
      * \param chan the channel index 0 to N-1
      */
-    virtual void set_tx_gain(double gain, const std::string &name, size_t chan) = 0;
+    virtual void set_tx_gain(double gain, const std::string &name, size_t chan = 0) = 0;
 
     //! A convenience wrapper for setting overall TX gain
-    void set_tx_gain(double gain, size_t chan){
+    void set_tx_gain(double gain, size_t chan = 0){
         return this->set_tx_gain(gain, ALL_GAINS, chan);
     }
 
@@ -450,10 +499,10 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the gain in dB
      */
-    virtual double get_tx_gain(const std::string &name, size_t chan) = 0;
+    virtual double get_tx_gain(const std::string &name, size_t chan = 0) = 0;
 
     //! A convenience wrapper for getting overall TX gain
-    double get_tx_gain(size_t chan){
+    double get_tx_gain(size_t chan = 0){
         return this->get_tx_gain(ALL_GAINS, chan);
     }
 
@@ -464,10 +513,10 @@ public:
      * \param chan the channel index 0 to N-1
      * \return a gain range object
      */
-    virtual gain_range_t get_tx_gain_range(const std::string &name, size_t chan) = 0;
+    virtual gain_range_t get_tx_gain_range(const std::string &name, size_t chan = 0) = 0;
 
     //! A convenience wrapper for getting overall TX gain range
-    gain_range_t get_tx_gain_range(size_t chan){
+    gain_range_t get_tx_gain_range(size_t chan = 0){
         return this->get_tx_gain_range(ALL_GAINS, chan);
     }
 
@@ -477,49 +526,49 @@ public:
      * \param chan the channel index 0 to N-1
      * \return a vector of gain element names
      */
-    virtual std::vector<std::string> get_tx_gain_names(size_t chan) = 0;
+    virtual std::vector<std::string> get_tx_gain_names(size_t chan = 0) = 0;
 
     /*!
      * Select the TX antenna on the subdevice.
      * \param ant the antenna name
      * \param chan the channel index 0 to N-1
      */
-    virtual void set_tx_antenna(const std::string &ant, size_t chan) = 0;
+    virtual void set_tx_antenna(const std::string &ant, size_t chan = 0) = 0;
 
     /*!
      * Get the selected TX antenna on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return the antenna name
      */
-    virtual std::string get_tx_antenna(size_t chan) = 0;
+    virtual std::string get_tx_antenna(size_t chan = 0) = 0;
 
     /*!
      * Get a list of possible TX antennas on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return a vector of antenna names
      */
-    virtual std::vector<std::string> get_tx_antennas(size_t chan) = 0;
+    virtual std::vector<std::string> get_tx_antennas(size_t chan = 0) = 0;
 
     /*!
      * Get the locked status of the LO on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return true for locked
      */
-    virtual bool get_tx_lo_locked(size_t chan) = 0;
+    virtual bool get_tx_lo_locked(size_t chan = 0) = 0;
 
     /*!
      * Set the TX bandwidth on the subdevice.
      * \param bandwidth the bandwidth in Hz
      * \param chan the channel index 0 to N-1
      */
-    virtual void set_tx_bandwidth(double bandwidth, size_t chan) = 0;
+    virtual void set_tx_bandwidth(double bandwidth, size_t chan = 0) = 0;
 
     /*!
      * Get the TX bandwidth on the subdevice.
      * \param chan the channel index 0 to N-1
      * \return the bandwidth in Hz
      */
-    virtual double get_tx_bandwidth(size_t chan) = 0;
+    virtual double get_tx_bandwidth(size_t chan = 0) = 0;
 
     /*!
      * Get the dboard interface object for the TX subdevice.
@@ -528,7 +577,7 @@ public:
      * \param chan the channel index 0 to N-1
      * \return the dboard interface sptr
      */
-    virtual dboard_iface::sptr get_tx_dboard_iface(size_t chan) = 0;
+    virtual dboard_iface::sptr get_tx_dboard_iface(size_t chan = 0) = 0;
 };
 
 }}
diff --git a/host/include/uhd/usrp/single_usrp.hpp b/host/include/uhd/usrp/single_usrp.hpp
index d80999300..0520db162 100644
--- a/host/include/uhd/usrp/single_usrp.hpp
+++ b/host/include/uhd/usrp/single_usrp.hpp
@@ -18,441 +18,12 @@
 #ifndef INCLUDED_UHD_USRP_SINGLE_USRP_HPP
 #define INCLUDED_UHD_USRP_SINGLE_USRP_HPP
 
-#include <uhd/config.hpp>
-#include <uhd/device.hpp>
-#include <uhd/types/ranges.hpp>
-#include <uhd/types/stream_cmd.hpp>
-#include <uhd/types/clock_config.hpp>
-#include <uhd/types/tune_request.hpp>
-#include <uhd/types/tune_result.hpp>
-#include <uhd/usrp/subdev_spec.hpp>
-#include <uhd/usrp/dboard_iface.hpp>
-#include <boost/shared_ptr.hpp>
-#include <boost/utility.hpp>
-#include <vector>
+#include <uhd/usrp/multi_usrp.hpp>
 
 namespace uhd{ namespace usrp{
 
-/*!
- * The single-USRP device class:
- * A single-USRP facilitates ease-of-use for most use-case scenarios.
- * The wrapper provides convenience functions to tune the devices
- * as well as to set the dboard gains, antennas, and other properties.
- * This wrapper supports multi-channel configurations per motherboard.
- */
-class UHD_API single_usrp : boost::noncopyable{
-public:
-    typedef boost::shared_ptr<single_usrp> sptr;
-
-    //! A wildcard gain element name
-    static const std::string ALL_GAINS;
-
-    /*!
-     * Make a new single usrp from the device address.
-     * \param dev_addr the device address
-     * \return a new single usrp object
-     */
-    static sptr make(const device_addr_t &dev_addr);
-
-    /*!
-     * Get the underlying device object.
-     * This is needed to get access to the streaming API and properties.
-     * \return the device object within this single usrp
-     */
-    virtual device::sptr get_device(void) = 0;
-
-    /*******************************************************************
-     * Mboard methods
-     ******************************************************************/
-    /*!
-     * Get a printable summary for this USRP configuration.
-     * \return a printable string
-     */
-    virtual std::string get_pp_string(void) = 0;
-
-    /*!
-     * Get canonical name for this USRP motherboard.
-     * \return a string representing the name
-     */
-    virtual std::string get_mboard_name(void) = 0;
-
-    /*!
-     * Get the current time in the usrp time registers.
-     * \return a timespec representing current usrp time
-     */
-    virtual time_spec_t get_time_now(void) = 0;
-
-    /*!
-     * Get the time when the last pps pulse occured.
-     * \return a timespec representing the last pps
-     */
-    virtual time_spec_t get_time_last_pps(void) = 0;
-
-    /*!
-     * Sets the time registers on the usrp immediately.
-     * \param time_spec the time to latch into the usrp device
-     */
-    virtual void set_time_now(const time_spec_t &time_spec) = 0;
-
-    /*!
-     * Set the time registers on the usrp at the next pps tick.
-     * The values will not be latched in until the pulse occurs.
-     * It is recommended that the user sleep(1) after calling to ensure
-     * that the time registers will be in a known state prior to use.
-     *
-     * Note: Because this call sets the time on the "next" pps,
-     * the seconds in the time spec should be current seconds + 1.
-     *
-     * \param time_spec the time to latch into the usrp device
-     */
-    virtual void set_time_next_pps(const time_spec_t &time_spec) = 0;
-
-    /*!
-     * Issue a stream command to the usrp device.
-     * This tells the usrp to send samples into the host.
-     * See the documentation for stream_cmd_t for more info.
-     * \param stream_cmd the stream command to issue
-     */
-    virtual void issue_stream_cmd(const stream_cmd_t &stream_cmd) = 0;
-
-    /*!
-     * Set the clock configuration for the usrp device.
-     * This tells the usrp how to get a 10Mhz reference and PPS clock.
-     * See the documentation for clock_config_t for more info.
-     * \param clock_config the clock configuration to set
-     */
-    virtual void set_clock_config(const clock_config_t &clock_config) = 0;
-
-    /*******************************************************************
-     * RX methods
-     ******************************************************************/
-    /*!
-     * Set the RX subdevice specification:
-     * The subdev spec maps a physical part of a daughter-board to a channel number.
-     * Set the subdev spec before calling into any methods with a channel number.
-     * \param spec the new subdevice specification
-     */
-    virtual void set_rx_subdev_spec(const uhd::usrp::subdev_spec_t &spec) = 0;
-
-    /*!
-     * Get the RX subdevice specification.
-     * \return the subdevice specification in use
-     */
-    virtual uhd::usrp::subdev_spec_t get_rx_subdev_spec(void) = 0;
-
-    /*!
-     * Get the name of the RX subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the subdevice name
-     */
-    virtual std::string get_rx_subdev_name(size_t chan = 0) = 0;
-
-    /*!
-     * Set the RX sample rate across all channels.
-     * \param rate the rate in Sps
-     */
-    virtual void set_rx_rate(double rate) = 0;
-
-    /*!
-     * Gets the RX sample rate for all channels.
-     * \return the rate in Sps
-     */
-    virtual double get_rx_rate(void) = 0;
-
-    /*!
-     * Set the RX center frequency.
-     * \param tune_request tune request instructions
-     * \param chan the channel index 0 to N-1
-     * \return a tune result object
-     */
-    virtual tune_result_t set_rx_freq(
-        const tune_request_t &tune_request, size_t chan = 0
-    ) = 0;
-
-    /*!
-     * Get the RX center frequency.
-     * \param chan the channel index 0 to N-1
-     * \return the frequency in Hz
-     */
-    virtual double get_rx_freq(size_t chan = 0) = 0;
-
-    /*!
-     * Get the RX center frequency range.
-     * \param chan the channel index 0 to N-1
-     * \return a frequency range object
-     */
-    virtual freq_range_t get_rx_freq_range(size_t chan = 0) = 0;
-
-    /*!
-     * Set the RX gain value for the specified gain element.
-     * For an empty name, distribute across all gain elements.
-     * \param gain the gain in dB
-     * \param name the name of the gain element
-     * \param chan the channel index 0 to N-1
-     */
-    virtual void set_rx_gain(double gain, const std::string &name, size_t chan = 0) = 0;
-
-    //! A convenience wrapper for setting overall RX gain
-    void set_rx_gain(double gain, size_t chan = 0){
-        return this->set_rx_gain(gain, ALL_GAINS, chan);
-    }
-
-    /*!
-     * Get the RX gain value for the specified gain element.
-     * For an empty name, sum across all gain elements.
-     * \param name the name of the gain element
-     * \param chan the channel index 0 to N-1
-     * \return the gain in dB
-     */
-    virtual double get_rx_gain(const std::string &name, size_t chan = 0) = 0;
-
-    //! A convenience wrapper for getting overall RX gain
-    double get_rx_gain(size_t chan = 0){
-        return this->get_rx_gain(ALL_GAINS, chan);
-    }
-
-    /*!
-     * Get the RX gain range for the specified gain element.
-     * For an empty name, calculate the overall gain range.
-     * \param name the name of the gain element
-     * \param chan the channel index 0 to N-1
-     * \return a gain range object
-     */
-    virtual gain_range_t get_rx_gain_range(const std::string &name, size_t chan = 0) = 0;
-
-    //! A convenience wrapper for getting overall RX gain range
-    gain_range_t get_rx_gain_range(size_t chan = 0){
-        return this->get_rx_gain_range(ALL_GAINS, chan);
-    }
-
-    /*!
-     * Get the names of the gain elements in the RX chain.
-     * Gain elements are ordered from antenna to FPGA.
-     * \param chan the channel index 0 to N-1
-     * \return a vector of gain element names
-     */
-    virtual std::vector<std::string> get_rx_gain_names(size_t chan = 0) = 0;
-
-    /*!
-     * Select the RX antenna on the subdevice.
-     * \param ant the antenna name
-     * \param chan the channel index 0 to N-1
-     */
-    virtual void set_rx_antenna(const std::string &ant, size_t chan = 0) = 0;
-
-    /*!
-     * Get the selected RX antenna on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the antenna name
-     */
-    virtual std::string get_rx_antenna(size_t chan = 0) = 0;
-
-    /*!
-     * Get a list of possible RX antennas on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return a vector of antenna names
-     */
-    virtual std::vector<std::string> get_rx_antennas(size_t chan = 0) = 0;
-
-    /*!
-     * Get the locked status of the LO on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return true for locked
-     */
-    virtual bool get_rx_lo_locked(size_t chan = 0) = 0;
-
-    /*!
-     * Set the RX bandwidth on the subdevice.
-     * \param bandwidth the bandwidth in Hz
-     * \param chan the channel index 0 to N-1
-     */
-    virtual void set_rx_bandwidth(double bandwidth, size_t chan = 0) = 0;
-
-    /*!
-     * Get the RX bandwidth on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the bandwidth in Hz
-     */
-    virtual double get_rx_bandwidth(size_t chan = 0) = 0;
-
-    /*!
-     * Read the RSSI value on the RX subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the rssi in dB
-     * \throw exception if RSSI readback not supported
-     */
-    virtual double read_rssi(size_t chan = 0) = 0;
-
-    /*!
-     * Get the dboard interface object for the RX subdevice.
-     * The dboard interface gives access to GPIOs, SPI, I2C, low-speed ADC and DAC.
-     * Use at your own risk!
-     * \param chan the channel index 0 to N-1
-     * \return the dboard interface sptr
-     */
-    virtual dboard_iface::sptr get_rx_dboard_iface(size_t chan = 0) = 0;
-
-    /*******************************************************************
-     * TX methods
-     ******************************************************************/
-    /*!
-     * Set the TX subdevice specification:
-     * The subdev spec maps a physical part of a daughter-board to a channel number.
-     * Set the subdev spec before calling into any methods with a channel number.
-     * \param spec the new subdevice specification
-     */
-    virtual void set_tx_subdev_spec(const uhd::usrp::subdev_spec_t &spec) = 0;
-
-    /*!
-     * Get the TX subdevice specification.
-     * \return the subdevice specification in use
-     */
-    virtual uhd::usrp::subdev_spec_t get_tx_subdev_spec(void) = 0;
-
-    /*!
-     * Get the name of the TX subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the subdevice name
-     */
-    virtual std::string get_tx_subdev_name(size_t chan = 0) = 0;
-
-    /*!
-     * Set the TX sample rate across all channels.
-     * \param rate the rate in Sps
-     */
-    virtual void set_tx_rate(double rate) = 0;
-
-    /*!
-     * Gets the TX sample rate for all channels.
-     * \return the rate in Sps
-     */
-    virtual double get_tx_rate(void) = 0;
-
-    /*!
-     * Set the TX center frequency.
-     * \param tune_request tune request instructions
-     * \param chan the channel index 0 to N-1
-     * \return a tune result object
-     */
-    virtual tune_result_t set_tx_freq(
-        const tune_request_t &tune_request, size_t chan = 0
-    ) = 0;
-
-    /*!
-     * Get the TX center frequency.
-     * \param chan the channel index 0 to N-1
-     * \return the frequency in Hz
-     */
-    virtual double get_tx_freq(size_t chan = 0) = 0;
-
-    /*!
-     * Get the TX center frequency range.
-     * \param chan the channel index 0 to N-1
-     * \return a frequency range object
-     */
-    virtual freq_range_t get_tx_freq_range(size_t chan = 0) = 0;
-
-    /*!
-     * Set the TX gain value for the specified gain element.
-     * For an empty name, distribute across all gain elements.
-     * \param gain the gain in dB
-     * \param name the name of the gain element
-     * \param chan the channel index 0 to N-1
-     */
-    virtual void set_tx_gain(double gain, const std::string &name, size_t chan = 0) = 0;
-
-    //! A convenience wrapper for setting overall TX gain
-    void set_tx_gain(double gain, size_t chan = 0){
-        return this->set_tx_gain(gain, ALL_GAINS, chan);
-    }
-
-    /*!
-     * Get the TX gain value for the specified gain element.
-     * For an empty name, sum across all gain elements.
-     * \param name the name of the gain element
-     * \param chan the channel index 0 to N-1
-     * \return the gain in dB
-     */
-    virtual double get_tx_gain(const std::string &name, size_t chan = 0) = 0;
-
-    //! A convenience wrapper for getting overall TX gain
-    double get_tx_gain(size_t chan = 0){
-        return this->get_tx_gain(ALL_GAINS, chan);
-    }
-
-    /*!
-     * Get the TX gain range for the specified gain element.
-     * For an empty name, calculate the overall gain range.
-     * \param name the name of the gain element
-     * \param chan the channel index 0 to N-1
-     * \return a gain range object
-     */
-    virtual gain_range_t get_tx_gain_range(const std::string &name, size_t chan = 0) = 0;
-
-    //! A convenience wrapper for getting overall TX gain range
-    gain_range_t get_tx_gain_range(size_t chan = 0){
-        return this->get_tx_gain_range(ALL_GAINS, chan);
-    }
-
-    /*!
-     * Get the names of the gain elements in the TX chain.
-     * Gain elements are ordered from antenna to FPGA.
-     * \param chan the channel index 0 to N-1
-     * \return a vector of gain element names
-     */
-    virtual std::vector<std::string> get_tx_gain_names(size_t chan = 0) = 0;
-
-    /*!
-     * Select the TX antenna on the subdevice.
-     * \param ant the antenna name
-     * \param chan the channel index 0 to N-1
-     */
-    virtual void set_tx_antenna(const std::string &ant, size_t chan = 0) = 0;
-
-    /*!
-     * Get the selected TX antenna on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the antenna name
-     */
-    virtual std::string get_tx_antenna(size_t chan = 0) = 0;
-
-    /*!
-     * Get a list of possible TX antennas on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return a vector of antenna names
-     */
-    virtual std::vector<std::string> get_tx_antennas(size_t chan = 0) = 0;
-
-    /*!
-     * Get the locked status of the LO on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return true for locked
-     */
-    virtual bool get_tx_lo_locked(size_t chan = 0) = 0;
-
-    /*!
-     * Set the TX bandwidth on the subdevice.
-     * \param bandwidth the bandwidth in Hz
-     * \param chan the channel index 0 to N-1
-     */
-    virtual void set_tx_bandwidth(double bandwidth, size_t chan = 0) = 0;
-
-    /*!
-     * Get the TX bandwidth on the subdevice.
-     * \param chan the channel index 0 to N-1
-     * \return the bandwidth in Hz
-     */
-    virtual double get_tx_bandwidth(size_t chan = 0) = 0;
-
-    /*!
-     * Get the dboard interface object for the TX subdevice.
-     * The dboard interface gives access to GPIOs, SPI, I2C, low-speed ADC and DAC.
-     * Use at your own risk!
-     * \param chan the channel index 0 to N-1
-     * \return the dboard interface sptr
-     */
-    virtual dboard_iface::sptr get_tx_dboard_iface(size_t chan = 0) = 0;
-};
+    //! Multi-USRP is a superset of Single-USRP
+    typedef multi_usrp single_usrp;
 
 }}
 
diff --git a/host/lib/transport/if_addrs.cpp b/host/lib/transport/if_addrs.cpp
index ad9a2325b..17cf8455b 100644
--- a/host/lib/transport/if_addrs.cpp
+++ b/host/lib/transport/if_addrs.cpp
@@ -42,6 +42,7 @@ std::vector<uhd::transport::if_addrs_t> uhd::transport::get_if_addrs(void){
     if (getifaddrs(&ifap) == 0){
         for (struct ifaddrs *iter = ifap; iter != NULL; iter = iter->ifa_next){
             //ensure that the entries are valid
+            if (iter->ifa_addr == NULL) continue;
             if (iter->ifa_addr->sa_family != AF_INET) continue;
             if (iter->ifa_netmask->sa_family != AF_INET) continue;
             if (iter->ifa_broadaddr->sa_family != AF_INET) continue;
diff --git a/host/lib/transport/udp_zero_copy_asio.cpp b/host/lib/transport/udp_zero_copy_asio.cpp
index 5c049cfad..697e172cd 100644
--- a/host/lib/transport/udp_zero_copy_asio.cpp
+++ b/host/lib/transport/udp_zero_copy_asio.cpp
@@ -24,7 +24,7 @@
 #include <uhd/utils/warning.hpp>
 #include <boost/asio.hpp>
 #include <boost/format.hpp>
-#include <boost/thread.hpp>
+#include <boost/thread/thread.hpp>
 #include <boost/enable_shared_from_this.hpp>
 #include <iostream>
 
@@ -32,9 +32,6 @@ using namespace uhd;
 using namespace uhd::transport;
 namespace asio = boost::asio;
 
-/***********************************************************************
- * Constants
- **********************************************************************/
 //Define this to the the boost async io calls to perform receive.
 //Otherwise, get_recv_buff uses a blocking receive with timeout.
 #define USE_ASIO_ASYNC_RECV
@@ -43,32 +40,6 @@ namespace asio = boost::asio;
 //Otherwise, the commit callback uses a blocking send.
 //#define USE_ASIO_ASYNC_SEND
 
-//By default, this buffer is sized insufficiently small.
-//For peformance, this buffer should be 10s of megabytes.
-static const size_t MIN_RECV_SOCK_BUFF_SIZE = size_t(10e3);
-
-//Large buffers cause more underflow at high rates.
-//Perhaps this is due to the kernel scheduling,
-//but may change with host-based flow control.
-static const size_t MIN_SEND_SOCK_BUFF_SIZE = size_t(10e3);
-
-//The number of async frames to allocate for each send and recv:
-//The non-async recv can have a very large number of recv frames
-//because the CPU overhead is independent of the number of frames.
-#ifdef USE_ASIO_ASYNC_RECV
-static const size_t DEFAULT_NUM_RECV_FRAMES = 32;
-#else
-static const size_t DEFAULT_NUM_RECV_FRAMES = MIN_RECV_SOCK_BUFF_SIZE/udp_simple::mtu;
-#endif
-
-//The non-async send only ever requires a single frame
-//because the buffer will be committed before a new get.
-#ifdef USE_ASIO_ASYNC_SEND
-static const size_t DEFAULT_NUM_SEND_FRAMES = 32;
-#else
-static const size_t DEFAULT_NUM_SEND_FRAMES = MIN_SEND_SOCK_BUFF_SIZE/udp_simple::mtu;
-#endif
-
 //The number of service threads to spawn for async ASIO:
 //A single concurrent thread for io_service seems to be the fastest.
 //Threads are disabled when no async implementations are enabled.
@@ -78,6 +49,9 @@ static const size_t CONCURRENCY_HINT = 1;
 static const size_t CONCURRENCY_HINT = 0;
 #endif
 
+//A reasonable number of frames for send/recv and async/sync
+static const size_t DEFAULT_NUM_FRAMES = 32;
+
 /***********************************************************************
  * Zero Copy UDP implementation with ASIO:
  *   This is the portable zero copy implementation for systems
@@ -95,9 +69,9 @@ public:
         const device_addr_t &hints
     ):
         _recv_frame_size(size_t(hints.cast<double>("recv_frame_size", udp_simple::mtu))),
-        _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_RECV_FRAMES))),
+        _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_FRAMES))),
         _send_frame_size(size_t(hints.cast<double>("send_frame_size", udp_simple::mtu))),
-        _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_SEND_FRAMES))),
+        _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_FRAMES))),
         _concurrency_hint(hints.cast<size_t>("concurrency_hint", CONCURRENCY_HINT)),
         _io_service(_concurrency_hint)
     {
@@ -325,16 +299,11 @@ template<typename Opt> static void resize_buff_helper(
     const size_t target_size,
     const std::string &name
 ){
-    size_t min_sock_buff_size = 0;
-    if (name == "recv") min_sock_buff_size = MIN_RECV_SOCK_BUFF_SIZE;
-    if (name == "send") min_sock_buff_size = MIN_SEND_SOCK_BUFF_SIZE;
-    min_sock_buff_size = std::max(min_sock_buff_size, target_size);
-
     std::string help_message;
     #if defined(UHD_PLATFORM_LINUX)
         help_message = str(boost::format(
             "Please run: sudo sysctl -w net.core.%smem_max=%d\n"
-        ) % ((name == "recv")?"r":"w") % min_sock_buff_size);
+        ) % ((name == "recv")?"r":"w") % target_size);
     #endif /*defined(UHD_PLATFORM_LINUX)*/
 
     //resize the buffer if size was provided
@@ -348,19 +317,10 @@ template<typename Opt> static void resize_buff_helper(
             "Current %s sock buff size: %d bytes"
         ) % name % actual_size << std::endl;
         if (actual_size < target_size) uhd::warning::post(str(boost::format(
-            "The %s buffer is smaller than the requested size.\n"
-            "The minimum requested buffer size is %d bytes.\n"
+            "The %s buffer could not be resized sufficiently.\n"
             "See the transport application notes on buffer resizing.\n%s"
-        ) % name % min_sock_buff_size % help_message));
-    }
-
-    //only enable on platforms that are happy with the large buffer resize
-    #if defined(UHD_PLATFORM_LINUX) || defined(UHD_PLATFORM_WIN32)
-    //otherwise, ensure that the buffer is at least the minimum size
-    else if (udp_trans->get_buff_size<Opt>() < min_sock_buff_size){
-        resize_buff_helper<Opt>(udp_trans, min_sock_buff_size, name);
+        ) % name % help_message));
     }
-    #endif /*defined(UHD_PLATFORM_LINUX) || defined(UHD_PLATFORM_WIN32)*/
 }
 
 udp_zero_copy::sptr udp_zero_copy::make(
diff --git a/host/lib/usrp/CMakeLists.txt b/host/lib/usrp/CMakeLists.txt
index bd25aec2b..97a54a798 100644
--- a/host/lib/usrp/CMakeLists.txt
+++ b/host/lib/usrp/CMakeLists.txt
@@ -29,7 +29,6 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/mboard_eeprom.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/misc_utils.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/multi_usrp.cpp
-    ${CMAKE_CURRENT_SOURCE_DIR}/single_usrp.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/subdev_spec.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/tune_helper.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/wrapper_utils.hpp
diff --git a/host/lib/usrp/gps_ctrl.cpp b/host/lib/usrp/gps_ctrl.cpp
index 3c7c00134..b1062fa39 100644
--- a/host/lib/usrp/gps_ctrl.cpp
+++ b/host/lib/usrp/gps_ctrl.cpp
@@ -58,7 +58,7 @@ public:
       if(trim_right_copy(reply) == "Command Error") {
         gps_type = GPS_TYPE_JACKSON_LABS;
         break;
-      }
+      } 
       else if(reply.substr(0, 3) == "$GP") i_heard_some_nmea = true; //but keep looking for that "Command Error" response
       else if(reply.length() != 0) i_heard_something_weird = true; //probably wrong baud rate
       boost::this_thread::sleep(boost::posix_time::milliseconds(200));
@@ -104,6 +104,7 @@ public:
           found_gprmc = true;
           break;
         }
+        boost::this_thread::sleep(boost::posix_time::milliseconds(200));
       }
       if(!found_gprmc) {
         if(gps_type == GPS_TYPE_JACKSON_LABS) std::cout << "Firefly GPS not locked or warming up." << std::endl;
@@ -127,16 +128,7 @@ public:
 
 //TODO: this isn't generalizeable to non-USRP2 USRPs.
   std::string safe_gps_read() {
-    std::string reply;
-    try {
-        reply = _recv();
-    } catch (std::runtime_error err) {
-      if(err.what() != std::string("usrp2 no control response")) throw; //sorry can't cope with that
-      else { //we don't actually have a GPS installed
-        reply = std::string();
-      }
-    }
-    return reply;
+    return _recv();
   }
 
   ptime get_time(void) {
@@ -196,7 +188,7 @@ private:
     GPS_TYPE_NONE
   } gps_type;
 
-  static const int GPS_TIMEOUT_TRIES = 5;
+  static const int GPS_TIMEOUT_TRIES = 10;
   static const int GPS_TIMEOUT_DELAY_MS = 200;
   static const int FIREFLY_STUPID_DELAY_MS = 200;
 
diff --git a/host/lib/usrp/multi_usrp.cpp b/host/lib/usrp/multi_usrp.cpp
index 48eec28c1..817d7b085 100644
--- a/host/lib/usrp/multi_usrp.cpp
+++ b/host/lib/usrp/multi_usrp.cpp
@@ -53,11 +53,26 @@ public:
     /*******************************************************************
      * Mboard methods
      ******************************************************************/
+    void set_master_clock_rate(double rate, size_t mboard){
+        if (mboard != ALL_MBOARDS){
+            _mboard(mboard)[MBOARD_PROP_CLOCK_RATE] = rate;
+            return;
+        }
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            set_master_clock_rate(rate, m);
+        }
+    }
+
+    double get_master_clock_rate(size_t mboard){
+        return _mboard(mboard)[MBOARD_PROP_CLOCK_RATE].as<double>();
+    }
+
     std::string get_pp_string(void){
         std::string buff = str(boost::format(
-            "Multi USRP:\n"
+            "%s USRP:\n"
             "  Device: %s\n"
         )
+            % ((get_num_mboards() > 1)? "Multi" : "Single")
             % (*_dev)[DEVICE_PROP_NAME].as<std::string>()
         );
         for (size_t m = 0; m < get_num_mboards(); m++){
@@ -121,6 +136,16 @@ public:
         return _mboard(0)[MBOARD_PROP_TIME_PPS].as<time_spec_t>();
     }
 
+    void set_time_now(const time_spec_t &time_spec, size_t mboard){
+        if (mboard != ALL_MBOARDS){
+            _mboard(mboard)[MBOARD_PROP_TIME_NOW] = time_spec;
+            return;
+        }
+        for (size_t m = 0; m < get_num_mboards(); m++){
+            set_time_now(time_spec, m);
+        }
+    }
+
     void set_time_next_pps(const time_spec_t &time_spec){
         for (size_t m = 0; m < get_num_mboards(); m++){
             _mboard(m)[MBOARD_PROP_TIME_PPS] = time_spec;
diff --git a/host/lib/usrp/single_usrp.cpp b/host/lib/usrp/single_usrp.cpp
deleted file mode 100644
index c37449c5f..000000000
--- a/host/lib/usrp/single_usrp.cpp
+++ /dev/null
@@ -1,339 +0,0 @@
-//
-// Copyright 2010-2011 Ettus Research LLC
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-//
-
-#include "wrapper_utils.hpp"
-#include <uhd/usrp/single_usrp.hpp>
-#include <uhd/usrp/tune_helper.hpp>
-#include <uhd/utils/assert.hpp>
-#include <uhd/utils/gain_group.hpp>
-#include <uhd/usrp/subdev_props.hpp>
-#include <uhd/usrp/mboard_props.hpp>
-#include <uhd/usrp/device_props.hpp>
-#include <uhd/usrp/dboard_props.hpp>
-#include <uhd/usrp/dsp_props.hpp>
-#include <boost/foreach.hpp>
-#include <boost/format.hpp>
-#include <stdexcept>
-#include <iostream>
-
-using namespace uhd;
-using namespace uhd::usrp;
-
-const std::string single_usrp::ALL_GAINS = "";
-
-/***********************************************************************
- * Simple USRP Implementation
- **********************************************************************/
-class single_usrp_impl : public single_usrp{
-public:
-    single_usrp_impl(const device_addr_t &addr){
-        _dev = device::make(addr);
-    }
-
-    device::sptr get_device(void){
-        return _dev;
-    }
-
-    /*******************************************************************
-     * Mboard methods
-     ******************************************************************/
-    std::string get_pp_string(void){
-        std::string buff = str(boost::format(
-            "Single USRP:\n"
-            "  Device: %s\n"
-            "  Mboard: %s\n"
-        )
-            % (*_dev)[DEVICE_PROP_NAME].as<std::string>()
-            % _mboard()[MBOARD_PROP_NAME].as<std::string>()
-        );
-
-        //----------- rx side of life ----------------------------------
-        buff += str(boost::format(
-            "  RX DSP: %s\n"
-        )
-            % _rx_dsp()[DSP_PROP_NAME].as<std::string>()
-        );
-        for (size_t chan = 0; chan < this->get_rx_subdev_spec().size(); chan++){
-            buff += str(boost::format(
-                "  RX Channel: %u\n"
-                "    RX Dboard: %s\n"
-                "    RX Subdev: %s\n"
-            ) % chan
-                % _rx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
-                % _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
-            );
-        }
-
-        //----------- tx side of life ----------------------------------
-        buff += str(boost::format(
-            "  TX DSP: %s\n"
-        )
-            % _tx_dsp()[DSP_PROP_NAME].as<std::string>()
-        );
-        for (size_t chan = 0; chan < this->get_tx_subdev_spec().size(); chan++){
-            buff += str(boost::format(
-                "  TX Channel: %u\n"
-                "    TX Dboard: %s\n"
-                "    TX Subdev: %s\n"
-            ) % chan
-                % _tx_dboard(chan)[DBOARD_PROP_NAME].as<std::string>()
-                % _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>()
-            );
-        }
-
-        return buff;
-    }
-
-    std::string get_mboard_name(void){
-        return _mboard()[MBOARD_PROP_NAME].as<std::string>();
-    }
-
-    time_spec_t get_time_now(void){
-        return _mboard()[MBOARD_PROP_TIME_NOW].as<time_spec_t>();
-    }
-
-    time_spec_t get_time_last_pps(void){
-        return _mboard()[MBOARD_PROP_TIME_PPS].as<time_spec_t>();
-    }
-
-    void set_time_now(const time_spec_t &time_spec){
-        _mboard()[MBOARD_PROP_TIME_NOW] = time_spec;
-    }
-
-    void set_time_next_pps(const time_spec_t &time_spec){
-        _mboard()[MBOARD_PROP_TIME_PPS] = time_spec;
-    }
-
-    void issue_stream_cmd(const stream_cmd_t &stream_cmd){
-        _mboard()[MBOARD_PROP_STREAM_CMD] = stream_cmd;
-    }
-
-    void set_clock_config(const clock_config_t &clock_config){
-        _mboard()[MBOARD_PROP_CLOCK_CONFIG] = clock_config;
-    }
-
-    /*******************************************************************
-     * RX methods
-     ******************************************************************/
-    void set_rx_subdev_spec(const subdev_spec_t &spec){
-        _mboard()[MBOARD_PROP_RX_SUBDEV_SPEC] = spec;
-    }
-
-    subdev_spec_t get_rx_subdev_spec(void){
-        return _mboard()[MBOARD_PROP_RX_SUBDEV_SPEC].as<subdev_spec_t>();
-    }
-
-    std::string get_rx_subdev_name(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>();
-    }
-
-    void set_rx_rate(double rate){
-        _rx_dsp()[DSP_PROP_HOST_RATE] = rate;
-        do_samp_rate_warning_message(rate, get_rx_rate(), "RX");
-    }
-
-    double get_rx_rate(void){
-        return _rx_dsp()[DSP_PROP_HOST_RATE].as<double>();
-    }
-
-    tune_result_t set_rx_freq(const tune_request_t &tune_request, size_t chan){
-        tune_result_t r = tune_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(), chan, tune_request);
-        do_tune_freq_warning_message(tune_request.target_freq, get_rx_freq(chan), "RX");
-        return r;
-    }
-
-    double get_rx_freq(size_t chan){
-        return derive_freq_from_rx_subdev_and_dsp(_rx_subdev(chan), _rx_dsp(), chan);
-    }
-
-    freq_range_t get_rx_freq_range(size_t chan){
-        return add_dsp_shift(_rx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _rx_dsp());
-    }
-
-    void set_rx_gain(double gain, const std::string &name, size_t chan){
-        return _rx_gain_group(chan)->set_value(gain, name);
-    }
-
-    double get_rx_gain(const std::string &name, size_t chan){
-        return _rx_gain_group(chan)->get_value(name);
-    }
-
-    gain_range_t get_rx_gain_range(const std::string &name, size_t chan){
-        return _rx_gain_group(chan)->get_range(name);
-    }
-
-    std::vector<std::string> get_rx_gain_names(size_t chan){
-        return _rx_gain_group(chan)->get_names();
-    }
-
-    void set_rx_antenna(const std::string &ant, size_t chan){
-        _rx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
-    }
-
-    std::string get_rx_antenna(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
-    }
-
-    std::vector<std::string> get_rx_antennas(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
-    }
-
-    bool get_rx_lo_locked(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
-    }
-
-    void set_rx_bandwidth(double bandwidth, size_t chan){
-        _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
-    }
-
-    double get_rx_bandwidth(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_BANDWIDTH].as<double>();
-    }
-
-    double read_rssi(size_t chan){
-        return _rx_subdev(chan)[SUBDEV_PROP_RSSI].as<double>();
-    }
-
-    dboard_iface::sptr get_rx_dboard_iface(size_t chan){
-        return _rx_dboard(chan)[DBOARD_PROP_DBOARD_IFACE].as<dboard_iface::sptr>();
-    }
-
-    /*******************************************************************
-     * TX methods
-     ******************************************************************/
-    void set_tx_subdev_spec(const subdev_spec_t &spec){
-        _mboard()[MBOARD_PROP_TX_SUBDEV_SPEC] = spec;
-    }
-
-    subdev_spec_t get_tx_subdev_spec(void){
-        return _mboard()[MBOARD_PROP_TX_SUBDEV_SPEC].as<subdev_spec_t>();
-    }
-
-    std::string get_tx_subdev_name(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_NAME].as<std::string>();
-    }
-
-    void set_tx_rate(double rate){
-        _tx_dsp()[DSP_PROP_HOST_RATE] = rate;
-        do_samp_rate_warning_message(rate, get_tx_rate(), "TX");
-    }
-
-    double get_tx_rate(void){
-        return _tx_dsp()[DSP_PROP_HOST_RATE].as<double>();
-    }
-
-    tune_result_t set_tx_freq(const tune_request_t &tune_request, size_t chan){
-        tune_result_t r = tune_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(), chan, tune_request);
-        do_tune_freq_warning_message(tune_request.target_freq, get_tx_freq(chan), "TX");
-        return r;
-    }
-
-    double get_tx_freq(size_t chan){
-        return derive_freq_from_tx_subdev_and_dsp(_tx_subdev(chan), _tx_dsp(), chan);
-    }
-
-    freq_range_t get_tx_freq_range(size_t chan){
-        return add_dsp_shift(_tx_subdev(chan)[SUBDEV_PROP_FREQ_RANGE].as<freq_range_t>(), _tx_dsp());
-    }
-
-    void set_tx_gain(double gain, const std::string &name, size_t chan){
-        return _tx_gain_group(chan)->set_value(gain, name);
-    }
-
-    double get_tx_gain(const std::string &name, size_t chan){
-        return _tx_gain_group(chan)->get_value(name);
-    }
-
-    gain_range_t get_tx_gain_range(const std::string &name, size_t chan){
-        return _tx_gain_group(chan)->get_range(name);
-    }
-
-    std::vector<std::string> get_tx_gain_names(size_t chan){
-        return _tx_gain_group(chan)->get_names();
-    }
-
-    void set_tx_antenna(const std::string &ant, size_t chan){
-        _tx_subdev(chan)[SUBDEV_PROP_ANTENNA] = ant;
-    }
-
-    std::string get_tx_antenna(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA].as<std::string>();
-    }
-
-    std::vector<std::string> get_tx_antennas(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_ANTENNA_NAMES].as<prop_names_t>();
-    }
-
-    bool get_tx_lo_locked(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_LO_LOCKED].as<bool>();
-    }
-
-    void set_tx_bandwidth(double bandwidth, size_t chan){
-        _tx_subdev(chan)[SUBDEV_PROP_BANDWIDTH] = bandwidth;
-    }
-
-    double get_tx_bandwidth(size_t chan){
-        return _tx_subdev(chan)[SUBDEV_PROP_BANDWIDTH].as<double>();
-    }
-
-    dboard_iface::sptr get_tx_dboard_iface(size_t chan){
-        return _tx_dboard(chan)[DBOARD_PROP_DBOARD_IFACE].as<dboard_iface::sptr>();
-    }
-
-private:
-    device::sptr _dev;
-    wax::obj _mboard(void){
-        return (*_dev)[DEVICE_PROP_MBOARD];
-    }
-    wax::obj _rx_dsp(void){
-        return _mboard()[MBOARD_PROP_RX_DSP];
-    }
-    wax::obj _tx_dsp(void){
-        return _mboard()[MBOARD_PROP_TX_DSP];
-    }
-    wax::obj _rx_dboard(size_t chan){
-        std::string db_name = this->get_rx_subdev_spec().at(chan).db_name;
-        return _mboard()[named_prop_t(MBOARD_PROP_RX_DBOARD, db_name)];
-    }
-    wax::obj _tx_dboard(size_t chan){
-        std::string db_name = this->get_tx_subdev_spec().at(chan).db_name;
-        return _mboard()[named_prop_t(MBOARD_PROP_TX_DBOARD, db_name)];
-    }
-    wax::obj _rx_subdev(size_t chan){
-        std::string sd_name = this->get_rx_subdev_spec().at(chan).sd_name;
-        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
-    }
-    wax::obj _tx_subdev(size_t chan){
-        std::string sd_name = this->get_tx_subdev_spec().at(chan).sd_name;
-        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_SUBDEV, sd_name)];
-    }
-    gain_group::sptr _rx_gain_group(size_t chan){
-        std::string sd_name = this->get_rx_subdev_spec().at(chan).sd_name;
-        return _rx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
-    }
-    gain_group::sptr _tx_gain_group(size_t chan){
-        std::string sd_name = this->get_tx_subdev_spec().at(chan).sd_name;
-        return _tx_dboard(chan)[named_prop_t(DBOARD_PROP_GAIN_GROUP, sd_name)].as<gain_group::sptr>();
-    }
-};
-
-/***********************************************************************
- * The Make Function
- **********************************************************************/
-single_usrp::sptr single_usrp::make(const device_addr_t &dev_addr){
-    return sptr(new single_usrp_impl(dev_addr));
-}
diff --git a/host/lib/usrp/subdev_spec.cpp b/host/lib/usrp/subdev_spec.cpp
index 51c88bda3..d5d950f1f 100644
--- a/host/lib/usrp/subdev_spec.cpp
+++ b/host/lib/usrp/subdev_spec.cpp
@@ -46,7 +46,7 @@ bool usrp::operator==(const subdev_spec_pair_t &lhs, const subdev_spec_pair_t &r
 
 subdev_spec_t::subdev_spec_t(const std::string &markup){
     BOOST_FOREACH(const std::string &pair, pair_tokenizer(markup)){
-        if (pair == "") continue;
+        if (pair.empty()) continue;
         std::vector<std::string> db_sd; boost::split(db_sd, pair, boost::is_any_of(":"));
         switch(db_sd.size()){
         case 1: this->push_back(subdev_spec_pair_t("", db_sd.front())); break;
diff --git a/host/lib/usrp/usrp1/clock_ctrl.cpp b/host/lib/usrp/usrp1/clock_ctrl.cpp
index 68c5f5320..156f2b0c4 100644
--- a/host/lib/usrp/usrp1/clock_ctrl.cpp
+++ b/host/lib/usrp/usrp1/clock_ctrl.cpp
@@ -29,32 +29,33 @@ using namespace uhd;
 /***********************************************************************
  * Constants
  **********************************************************************/
-static const double master_clock_rate = 64e6;
+static const double default_master_clock_rate = 64e6;
 
 /***********************************************************************
  * Clock Control Implementation
  **********************************************************************/
 class usrp1_clock_ctrl_impl : public usrp1_clock_ctrl {
 public:
-    usrp1_clock_ctrl_impl(usrp1_iface::sptr iface)
-    {
-        _iface = iface;
+    usrp1_clock_ctrl_impl(usrp1_iface::sptr iface): _iface(iface){
+        this->set_master_clock_freq(default_master_clock_rate);
     }
 
-    double get_master_clock_freq(void)
-    {
-        return master_clock_rate; 
+    void set_master_clock_freq(double freq){
+        _freq = freq;
+    }
+
+    double get_master_clock_freq(void){
+        return _freq;
     }
 
 private:
     usrp1_iface::sptr _iface;
-
+    double _freq;
 };
 
 /***********************************************************************
  * Clock Control Make
  **********************************************************************/
-usrp1_clock_ctrl::sptr usrp1_clock_ctrl::make(usrp1_iface::sptr iface)
-{
+usrp1_clock_ctrl::sptr usrp1_clock_ctrl::make(usrp1_iface::sptr iface){
     return sptr(new usrp1_clock_ctrl_impl(iface));
 }
diff --git a/host/lib/usrp/usrp1/clock_ctrl.hpp b/host/lib/usrp/usrp1/clock_ctrl.hpp
index 366869dab..645472f02 100644
--- a/host/lib/usrp/usrp1/clock_ctrl.hpp
+++ b/host/lib/usrp/usrp1/clock_ctrl.hpp
@@ -40,6 +40,13 @@ public:
     static sptr make(usrp1_iface::sptr iface);
 
     /*!
+     * Set the rate of the fpga clock line.
+     * Note: does not really set, its all software.
+     * \param freq the new clock rate in Hz
+     */
+    virtual void set_master_clock_freq(double freq) = 0;
+
+    /*!
      * Get the rate of the fpga clock line.
      * \return the fpga clock rate in Hz
      */
diff --git a/host/lib/usrp/usrp1/mboard_impl.cpp b/host/lib/usrp/usrp1/mboard_impl.cpp
index 23c8f03c4..6d5bf466d 100644
--- a/host/lib/usrp/usrp1/mboard_impl.cpp
+++ b/host/lib/usrp/usrp1/mboard_impl.cpp
@@ -317,6 +317,10 @@ void usrp1_impl::mboard_get(const wax::obj &key_, wax::obj &val)
         val = _soft_time_ctrl->get_time();
         return;
 
+    case MBOARD_PROP_CLOCK_RATE:
+        val = _clock_ctrl->get_master_clock_freq();
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -379,6 +383,10 @@ void usrp1_impl::mboard_set(const wax::obj &key, const wax::obj &val)
         _soft_time_ctrl->set_time(val.as<time_spec_t>());
         return;
 
+    case MBOARD_PROP_CLOCK_RATE:
+        _clock_ctrl->set_master_clock_freq(val.as<double>());
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/usrp1/soft_time_ctrl.cpp b/host/lib/usrp/usrp1/soft_time_ctrl.cpp
index 856faf89d..c91ecc7ed 100644
--- a/host/lib/usrp/usrp1/soft_time_ctrl.cpp
+++ b/host/lib/usrp/usrp1/soft_time_ctrl.cpp
@@ -69,6 +69,9 @@ public:
         _thread_group.create_thread(boost::bind(&soft_time_ctrl_impl::recv_cmd_dispatcher, this));
         _update_mutex.lock(); //lock blocks until spawned
         _update_mutex.unlock(); //unlock mutex before done
+
+        //initialize the time to something
+        this->set_time(time_spec_t(0.0));
     }
 
     ~soft_time_ctrl_impl(void){
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index 95f7013e7..784f662d9 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -66,9 +66,9 @@ usrp2_mboard_impl::usrp2_mboard_impl(
     //contruct the interfaces to mboard perifs
     _clock_ctrl = usrp2_clock_ctrl::make(_iface);
     _codec_ctrl = usrp2_codec_ctrl::make(_iface);
-    //_gps_ctrl = gps_ctrl::make(
-    //    _iface->get_gps_write_fn(),
-    //    _iface->get_gps_read_fn());
+//    _gps_ctrl = gps_ctrl::make(
+//        _iface->get_gps_write_fn(),
+//        _iface->get_gps_read_fn());
 
     //if(_gps_ctrl->gps_detected()) std::cout << "GPS time: " << _gps_ctrl->get_time() << std::endl;
 
@@ -243,6 +243,9 @@ void usrp2_mboard_impl::update_clock_config(void){
 }
 
 void usrp2_mboard_impl::set_time_spec(const time_spec_t &time_spec, bool now){
+    //dont set the time for slave devices, they always take from mimo cable
+    if (not _mimo_clocking_mode_is_master) return;
+
     //set the ticks
     _iface->poke32(_iface->regs.time64_ticks, time_spec.get_tick_count(get_master_clock_freq()));
 
@@ -352,6 +355,10 @@ void usrp2_mboard_impl::get(const wax::obj &key_, wax::obj &val){
         val = _iface->mb_eeprom;
         return;
 
+    case MBOARD_PROP_CLOCK_RATE:
+        val = this->get_master_clock_freq();
+        return;
+
     default: UHD_THROW_PROP_GET_ERROR();
     }
 }
@@ -409,6 +416,10 @@ void usrp2_mboard_impl::set(const wax::obj &key, const wax::obj &val){
         _iface->mb_eeprom = mboard_eeprom_t(*_iface, mboard_eeprom_t::MAP_N100);
         return;
 
+    case MBOARD_PROP_CLOCK_RATE:
+        UHD_ASSERT_THROW(val.as<double>() == this->get_master_clock_freq());
+        return;
+
     default: UHD_THROW_PROP_SET_ERROR();
     }
 }
diff --git a/host/lib/usrp/usrp2/usrp2_impl.cpp b/host/lib/usrp/usrp2/usrp2_impl.cpp
index 059ddf65f..9ce0f7359 100644
--- a/host/lib/usrp/usrp2/usrp2_impl.cpp
+++ b/host/lib/usrp/usrp2/usrp2_impl.cpp
@@ -202,8 +202,11 @@ static device::sptr usrp2_make(const device_addr_t &device_addr){
     //setup the dsp transport hints (default to a large recv buff)
     device_addr_t dsp_xport_hints = device_addr;
     if (not dsp_xport_hints.has_key("recv_buff_size")){
-        //set to half-a-second of buffering at max rate
-        dsp_xport_hints["recv_buff_size"] = "50e6";
+        //only enable on platforms that are happy with the large buffer resize
+        #if defined(UHD_PLATFORM_LINUX) || defined(UHD_PLATFORM_WIN32)
+            //set to half-a-second of buffering at max rate
+            dsp_xport_hints["recv_buff_size"] = "50e6";
+        #endif /*defined(UHD_PLATFORM_LINUX) || defined(UHD_PLATFORM_WIN32)*/
     }
 
     //create a ctrl and data transport for each address
diff --git a/host/lib/usrp/usrp_e100/clock_ctrl.cpp b/host/lib/usrp/usrp_e100/clock_ctrl.cpp
index a8d88fa42..05a27c38b 100644
--- a/host/lib/usrp/usrp_e100/clock_ctrl.cpp
+++ b/host/lib/usrp/usrp_e100/clock_ctrl.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright 2010 Ettus Research LLC
+// Copyright 2010-2011 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -18,17 +18,29 @@
 #include "clock_ctrl.hpp"
 #include "ad9522_regs.hpp"
 #include <uhd/utils/assert.hpp>
-#include <uhd/utils/static.hpp>
 #include <boost/cstdint.hpp>
 #include "usrp_e100_regs.hpp" //spi slave constants
 #include <boost/assign/list_of.hpp>
 #include <boost/foreach.hpp>
 #include <boost/format.hpp>
+#include <boost/operators.hpp>
+#include <boost/math/common_factor_rt.hpp> //gcd
+#include <algorithm>
 #include <utility>
 #include <iostream>
 
 using namespace uhd;
 
+/***********************************************************************
+ * Constants
+ **********************************************************************/
+static const bool ENABLE_THE_TEST_OUT = false;
+static const double REFERENCE_INPUT_RATE = 10e6;
+static const double DEFAULT_OUTPUT_RATE = 64e6;
+
+/***********************************************************************
+ * Helpers
+ **********************************************************************/
 template <typename div_type, typename bypass_type> static void set_clock_divider(
     size_t divider, div_type &low, div_type &high, bypass_type &bypass
 ){
@@ -41,13 +53,13 @@ template <typename div_type, typename bypass_type> static void set_clock_divider
  * Clock rate calculation stuff:
  *   Using the internal VCO between 1400 and 1800 MHz
  **********************************************************************/
-struct clock_settings_type{
-    size_t ref_clock_doubler, r_counter, a_counter, b_counter, prescaler, vco_divider, clk_divider;
+struct clock_settings_type : boost::totally_ordered<clock_settings_type>{
+    size_t ref_clock_doubler, r_counter, a_counter, b_counter, prescaler, vco_divider, chan_divider;
     size_t get_n_counter(void) const{return prescaler * b_counter + a_counter;}
-    double get_ref_rate(void) const{return 10e6 * ref_clock_doubler;}
+    double get_ref_rate(void) const{return REFERENCE_INPUT_RATE * ref_clock_doubler;}
     double get_vco_rate(void) const{return get_ref_rate()/r_counter * get_n_counter();}
-    double get_clk_rate(void) const{return get_vco_rate()/vco_divider;}
-    double get_out_rate(void) const{return get_clk_rate()/clk_divider;}
+    double get_chan_rate(void) const{return get_vco_rate()/vco_divider;}
+    double get_out_rate(void) const{return get_chan_rate()/chan_divider;}
     std::string to_pp_string(void) const{
         return str(boost::format(
             "  r_counter: %d\n"
@@ -55,9 +67,9 @@ struct clock_settings_type{
             "  b_counter: %d\n"
             "  prescaler: %d\n"
             "  vco_divider: %d\n"
-            "  clk_divider: %d\n"
+            "  chan_divider: %d\n"
             "  vco_rate: %fMHz\n"
-            "  clk_rate: %fMHz\n"
+            "  chan_rate: %fMHz\n"
             "  out_rate: %fMHz\n"
             )
             % r_counter
@@ -65,31 +77,43 @@ struct clock_settings_type{
             % b_counter
             % prescaler
             % vco_divider
-            % clk_divider
+            % chan_divider
             % (get_vco_rate()/1e6)
-            % (get_clk_rate()/1e6)
+            % (get_chan_rate()/1e6)
             % (get_out_rate()/1e6)
         );
     }
 };
 
-UHD_SINGLETON_FCN(std::vector<clock_settings_type>, get_clock_settings);
+bool operator<(const clock_settings_type &lhs, const clock_settings_type &rhs){
+    if (lhs.get_out_rate() != rhs.get_out_rate()) //sort small to large out rates
+        return lhs.get_out_rate() < rhs.get_out_rate();
+
+    if (lhs.r_counter != rhs.r_counter) //sort small to large r dividers
+        return lhs.r_counter < rhs.r_counter;
+
+    if (lhs.get_vco_rate() != rhs.get_vco_rate()) //sort large to small vco rates
+        return lhs.get_vco_rate() > rhs.get_vco_rate();
+
+    return false; //whatever case
+}
+
+static std::vector<clock_settings_type> _get_clock_settings(void){
+    std::vector<clock_settings_type> clock_settings;
 
-UHD_STATIC_BLOCK(libuhd_usrp_e100_reg_clock_rates){
     clock_settings_type cs;
     cs.ref_clock_doubler = 2; //always doubling
     cs.prescaler = 8; //set to 8 when input is under 2400 MHz
 
-    for (cs.r_counter = 1; cs.r_counter <= 1; cs.r_counter++){
+    for (cs.r_counter = 1; cs.r_counter <= 3; cs.r_counter++){
     for (cs.b_counter = 3; cs.b_counter <= 10; cs.b_counter++){
     for (cs.a_counter = 0; cs.a_counter <= 10; cs.a_counter++){
     for (cs.vco_divider = 2; cs.vco_divider <= 6; cs.vco_divider++){
-    for (cs.clk_divider = 1; cs.clk_divider <= 32; cs.clk_divider++){
+    for (cs.chan_divider = 1; cs.chan_divider <= 32; cs.chan_divider++){
         if (cs.get_vco_rate() > 1800e6) continue;
         if (cs.get_vco_rate() < 1400e6) continue;
         if (cs.get_out_rate() < 32e6) continue; //lowest we allow for GPMC interface
-        //std::cout << (cs.get_out_rate()/1e6) << std::endl;
-        get_clock_settings().push_back(cs);
+        clock_settings.push_back(cs);
     }}}}}
 }
 
@@ -105,30 +129,44 @@ class usrp_e100_clock_ctrl_impl : public usrp_e100_clock_ctrl{
 public:
     usrp_e100_clock_ctrl_impl(usrp_e100_iface::sptr iface){
         _iface = iface;
+        _chan_rate = 0.0;
+        _out_rate = 0.0;
 
         //init the clock gen registers
         //Note: out0 should already be clocking the FPGA or this isnt going to work
         _ad9522_regs.sdo_active = ad9522_regs_t::SDO_ACTIVE_SDO_SDIO;
         _ad9522_regs.enable_clock_doubler = 1; //enable ref clock doubler
         _ad9522_regs.enb_stat_eeprom_at_stat_pin = 0; //use status pin
-        _ad9522_regs.status_pin_control = 0x1; //n divider
+        _ad9522_regs.status_pin_control = 0x2; //r divider
         _ad9522_regs.ld_pin_control = 0x00; //dld
         _ad9522_regs.refmon_pin_control = 0x12; //show ref2
+        _ad9522_regs.lock_detect_counter = ad9522_regs_t::LOCK_DETECT_COUNTER_255CYC;
 
         this->use_internal_ref();
 
-        this->set_fpga_clock_rate(64e6); //initialize to something
+        this->set_fpga_clock_rate(DEFAULT_OUTPUT_RATE); //initialize to something
 
+        this->enable_test_clock(ENABLE_THE_TEST_OUT);
         this->enable_rx_dboard_clock(false);
         this->enable_tx_dboard_clock(false);
     }
 
     ~usrp_e100_clock_ctrl_impl(void){
+        this->enable_test_clock(ENABLE_THE_TEST_OUT);
         this->enable_rx_dboard_clock(false);
         this->enable_tx_dboard_clock(false);
     }
 
+    /***********************************************************************
+     * Clock rate control:
+     *  - set clock rate w/ internal VCO
+     *  - set clock rate w/ external VCXO
+     **********************************************************************/
     void set_clock_settings_with_internal_vco(const clock_settings_type &cs){
+        //set the rates to private variables so the implementation knows!
+        _chan_rate = cs.get_chan_rate();
+        _out_rate = cs.get_out_rate();
+
         _ad9522_regs.enable_clock_doubler = (cs.ref_clock_doubler == 2)? 1 : 0;
 
         _ad9522_regs.set_r_counter(cs.r_counter);
@@ -141,6 +179,7 @@ public:
         _ad9522_regs.cp_current = ad9522_regs_t::CP_CURRENT_1_2MA;
 
         _ad9522_regs.vco_calibration_now = 1; //calibrate it!
+        _ad9522_regs.bypass_vco_divider = 0;
         switch(cs.vco_divider){
         case 1: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV1; break;
         case 2: _ad9522_regs.vco_divider = ad9522_regs_t::VCO_DIVIDER_DIV2; break;
@@ -153,7 +192,7 @@ public:
 
         //setup fpga master clock
         _ad9522_regs.out0_format = ad9522_regs_t::OUT0_FORMAT_LVDS;
-        set_clock_divider(cs.clk_divider,
+        set_clock_divider(cs.chan_divider,
             _ad9522_regs.divider0_low_cycles,
             _ad9522_regs.divider0_high_cycles,
             _ad9522_regs.divider0_bypass
@@ -161,44 +200,60 @@ public:
 
         //setup codec clock
         _ad9522_regs.out3_format = ad9522_regs_t::OUT3_FORMAT_LVDS;
-        set_clock_divider(cs.clk_divider,
+        set_clock_divider(cs.chan_divider,
             _ad9522_regs.divider1_low_cycles,
             _ad9522_regs.divider1_high_cycles,
             _ad9522_regs.divider1_bypass
         );
 
-        //setup test clock (same divider as codec clock)
-        _ad9522_regs.out4_format = ad9522_regs_t::OUT4_FORMAT_CMOS;
-        _ad9522_regs.out4_cmos_configuration = (enable_test_clock)?
-            ad9522_regs_t::OUT4_CMOS_CONFIGURATION_A_ON :
-            ad9522_regs_t::OUT4_CMOS_CONFIGURATION_OFF;
+        this->send_all_regs();
+    }
 
-        //setup a list of register ranges to write
-        typedef std::pair<boost::uint16_t, boost::uint16_t> range_t;
-        static const std::vector<range_t> ranges = boost::assign::list_of
-            (range_t(0x000, 0x000)) (range_t(0x010, 0x01F))
-            (range_t(0x0F0, 0x0FD)) (range_t(0x190, 0x19B))
-            (range_t(0x1E0, 0x1E1)) (range_t(0x230, 0x230))
-        ;
+    void set_clock_settings_with_external_vcxo(double rate){
+        //set the rates to private variables so the implementation knows!
+        _chan_rate = rate;
+        _out_rate = rate;
 
-        //write initial register values and latch/update
-        BOOST_FOREACH(const range_t &range, ranges){
-            for(boost::uint16_t addr = range.first; addr <= range.second; addr++){
-                this->send_reg(addr);
-            }
-        }
-        this->latch_regs();
+        _ad9522_regs.enable_clock_doubler = 1; //doubler always on
+        const double ref_rate = REFERENCE_INPUT_RATE*2;
+
+        //bypass prescaler such that N = B
+        long gcd = boost::math::gcd(long(ref_rate), long(rate));
+        _ad9522_regs.set_r_counter(int(ref_rate/gcd));
+        _ad9522_regs.a_counter = 0;
+        _ad9522_regs.set_b_counter(int(rate/gcd));
+        _ad9522_regs.prescaler_p = ad9522_regs_t::PRESCALER_P_DIV1;
+
+        //setup external vcxo
+        _ad9522_regs.pll_power_down = ad9522_regs_t::PLL_POWER_DOWN_NORMAL;
+        _ad9522_regs.cp_current = ad9522_regs_t::CP_CURRENT_1_2MA;
+        _ad9522_regs.bypass_vco_divider = 1;
+        _ad9522_regs.select_vco_or_clock = ad9522_regs_t::SELECT_VCO_OR_CLOCK_EXTERNAL;
+
+        //setup fpga master clock
+        _ad9522_regs.out0_format = ad9522_regs_t::OUT0_FORMAT_LVDS;
+        _ad9522_regs.divider0_bypass = 1;
+
+        //setup codec clock
+        _ad9522_regs.out3_format = ad9522_regs_t::OUT3_FORMAT_LVDS;
+        _ad9522_regs.divider1_bypass = 1;
+
+        this->send_all_regs();
     }
 
     void set_fpga_clock_rate(double rate){
+        if (_out_rate == rate) return;
+
         if (rate == 61.44e6){
-            //TODO special settings for external VCXO
+            set_clock_settings_with_external_vcxo(rate);
         }
         else{
             BOOST_FOREACH(const clock_settings_type &cs, get_clock_settings()){
+                //std::cout << cs.to_pp_string() << std::endl;
                 if (rate != cs.get_out_rate()) continue;
                 std::cout << "USRP-E100 clock control:" << std::endl << cs.to_pp_string() << std::endl;
                 set_clock_settings_with_internal_vco(cs);
+                return; //done here, exits loop
             }
             throw std::runtime_error(str(boost::format(
                 "USRP-E100 clock control: could not find settings for clock rate %fMHz"
@@ -207,7 +262,20 @@ public:
     }
 
     double get_fpga_clock_rate(void){
-        return master_clock_rate/fpga_clock_divider;
+        return this->_out_rate;
+    }
+
+    /***********************************************************************
+     * Special test clock output
+     **********************************************************************/
+    void enable_test_clock(bool enb){
+        //setup test clock (same divider as codec clock)
+        _ad9522_regs.out4_format = ad9522_regs_t::OUT4_FORMAT_CMOS;
+        _ad9522_regs.out4_cmos_configuration = (enb)?
+            ad9522_regs_t::OUT4_CMOS_CONFIGURATION_A_ON :
+            ad9522_regs_t::OUT4_CMOS_CONFIGURATION_OFF;
+        this->send_reg(0x0F0);
+        this->latch_regs();
     }
 
     /***********************************************************************
@@ -225,13 +293,13 @@ public:
     std::vector<double> get_rx_dboard_clock_rates(void){
         std::vector<double> rates;
         for(size_t div = 1; div <= 16+16; div++)
-            rates.push_back(master_clock_rate/div);
+            rates.push_back(this->_chan_rate/div);
         return rates;
     }
 
     void set_rx_dboard_clock_rate(double rate){
         assert_has(get_rx_dboard_clock_rates(), rate, "rx dboard clock rate");
-        size_t divider = size_t(master_clock_rate/rate);
+        size_t divider = size_t(this->_chan_rate/rate);
         //set the divider registers
         set_clock_divider(divider,
             _ad9522_regs.divider3_low_cycles,
@@ -261,7 +329,7 @@ public:
 
     void set_tx_dboard_clock_rate(double rate){
         assert_has(get_tx_dboard_clock_rates(), rate, "tx dboard clock rate");
-        size_t divider = size_t(master_clock_rate/rate);
+        size_t divider = size_t(this->_chan_rate/rate);
         //set the divider registers
         set_clock_divider(divider,
             _ad9522_regs.divider2_low_cycles,
@@ -302,6 +370,8 @@ public:
 private:
     usrp_e100_iface::sptr _iface;
     ad9522_regs_t _ad9522_regs;
+    double _out_rate; //rate at the fpga and codec
+    double _chan_rate; //rate before final dividers
 
     void latch_regs(void){
         _ad9522_regs.io_update = 1;
@@ -317,6 +387,24 @@ private:
             reg, 24, false /*no rb*/
         );
     }
+
+    void send_all_regs(void){
+        //setup a list of register ranges to write
+        typedef std::pair<boost::uint16_t, boost::uint16_t> range_t;
+        static const std::vector<range_t> ranges = boost::assign::list_of
+            (range_t(0x000, 0x000)) (range_t(0x010, 0x01F))
+            (range_t(0x0F0, 0x0FD)) (range_t(0x190, 0x19B))
+            (range_t(0x1E0, 0x1E1)) (range_t(0x230, 0x230))
+        ;
+
+        //write initial register values and latch/update
+        BOOST_FOREACH(const range_t &range, ranges){
+            for(boost::uint16_t addr = range.first; addr <= range.second; addr++){
+                this->send_reg(addr);
+            }
+        }
+        this->latch_regs();
+    }
 };
 
 /***********************************************************************
diff --git a/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp b/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp
index 864e82099..df8e5dc9f 100644
--- a/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp
+++ b/host/lib/usrp/usrp_e100/usrp_e100_impl.hpp
@@ -30,7 +30,7 @@
 #ifndef INCLUDED_USRP_E100_IMPL_HPP
 #define INCLUDED_USRP_E100_IMPL_HPP
 
-static const boost::uint16_t USRP_E_COMPAT_NUM = 0x03;
+static const boost::uint16_t USRP_E_COMPAT_NUM = 0x02; //make this 3 then the mainline fpga image gets fixed for embedded
 
 //! load an fpga image from a bin file into the usrp-e fpga
 extern void usrp_e100_load_fpga(const std::string &bin_file);
diff --git a/host/lib/utils/paths.cpp b/host/lib/utils/paths.cpp
index 93d15d290..8d604d849 100644
--- a/host/lib/utils/paths.cpp
+++ b/host/lib/utils/paths.cpp
@@ -64,6 +64,7 @@ static std::vector<fs::path> get_env_paths(const std::string &var_name){
 
     //convert to filesystem path, filter blank paths
     std::vector<fs::path> paths;
+    if (var_value.empty()) return paths; //FIXME boost tokenizer throws w/ blank strings on some platforms
     BOOST_FOREACH(const std::string &path_string, path_tokenizer(var_value)){
         if (path_string.empty()) continue;
         paths.push_back(fs::system_complete(path_string));