We lamented the death of Ian Murdock [see Ian Murdock if this link goes down] noting that the Debian distribution he created continues to support the widest range of architectures. [Gabriella Coleman summarises his importance for free and open source software in Ian Murdock In His Own Words.]
Stephane mentioned his interest in software defined radio as he is currently studying for a radio operator’s licence. This led into two related discussions, one about FPGAs and the other about the Open Base Station Architecture Initiative which describes what is needed to set up a mobile base station.
Duncan spoke about Field Programmable Gate Arrays (FPGAS), some of which have the analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) useful in software defined radio. IBM has recently acquired Altera which, along with Xilinx, is one of the main providers of FPGAs. Xilinx produces the MicroBlaze, support for which was merged into the Linux kernel and GCC in 2009.
For learning about FPGAs, he suggested the Arty Artix or Basys boards which come with the Vivado toolkit. Unlike microprocessors which operate on a sequence of instructions, FPGAs are concurrent state machines.
Finally, in response to another comment, he noted that the OpenSPARC T2 had had many features which were later introduced on Intel chips.