So, it looks like I've not made any progress for a while. Well, that's not strictly true...
I've mostly been concerned myself writing a demo for the Amstrad CPC which will be released this weekend at the Sundown demo party. I won't provide a youtube link right now as it's not been officially presented yet, but here are some screenshots of the demo called sugarlumps (it's a chunky demo for the machine by Alan Sugar)...
Obviously, I'll post a youtube video and disk image when the demo has been officially released.
Back to CPCfpga, it's not been completely quiet. I've completely started again on the Atmega code and now have a reliable virtual serial port working which emulates the PACE serial adapter and instead of a "command monitor" on a serial port, I have a JTAG protocol so external programs can make arbitrary JTAG requests. That means all the JTAG boundary scan testing code I wrote for the raspberry pi can be used without massive changes and worrying about the memory space on the Atmega. The only problem is that the old JTAG interface sent and received a bit at a time, which is really slow over USB. I'm gradually migrating the important programs to use a block transfer which allows 512 bits to be transferred per USB packet.