Thanks John,
The past year, I left my RaspPi and Beagleboard in the drawer and started playing with the papilio board
http://papilio.cc/.You probably want to have a look at it! This solution is probably better than what you have + you won't have to deal with the missing ~ $20 FTDI.
Ultimately I have my eyes on the Xilinx ZynQ
http://zedboard.org/ http://www.xilinx.com/training/zynq/index.htmwhich offer the combination ARM + FPGA for ~ $400 / dev board
which is certainly more expensive than the RaspPi+FPGA solution, but more flexible and higher performance. I also predict that Intel + Altera will offer a similar SOC soon.
In the same space, I am looking at PoE and Qt Embedded.
Check this out
http://www.megaleecher.net/Raspberry_Pi_POE#axzz2tuLQEoyv http://www.ics.com/blog/building-qt-and-qtwayland-raspberry-pi#.UwaOhsv8NhFhttps://gitorious.org/raspberry-qt/raspberry-qt/source/3c2ed05270137644300cde3b22829380698ff9a9:README.txtNow imagine that you plug your embedded IOC, PVs are available but GUI are also deployed on a distributed file-system.
Cheers,
--
E
In the end I was, with relatively little work, able to write some HDL code for the FPGA, program the FPGA from the Pi over the USB connection, and then connect an IOC on the Pi to the FPGA via the USB connection, thus creating a simple stand alone data acquisition instrument with built-in IOC.