Since the mods look to be within (kinda) my abilities it seems like a fun thing to do. I don't yet have a parallel ZIP100 drive so no desktop for me but I have done some poking and investigating this evening.
Here is the little mainboard. It is very small. Can't remember how big the A7000 mainboard is but I think it is much bigger than this! There are a lot of pins on the ARM SOC that are not connected to anything.
It has RISC OS-NC (Network Computer presumably) ROM chips. Ian Jeffray says that nothing happens if you plug RO3.7 ROMs in. I also read that somewhere else that I can't find now. The person thought that might be due to the total lack of CMOS RAM circuitry, but I think that may not be true as I think most RISC OS machines drop to the supervisor prompt anyway if the CMOS RAM chip is missing. Though perhaps it is because the RO3.7 ROMS don't have the module to switch the SCART socket on.
Here is the IO chip that cunning bodgery may need to speak to:
To the right of the ROM chips is a solder point for a mysterious and quite big connector that seems to be routed to the ROM chips. No idea what this can be for.
The modem, which is part of the mainboard seems to appear to RISC OS as a podule. It has an accompanying MODEM module. This is not in the main ROM chips, but lives in this little PROM. I confirmed this by removing the PROM which made the module disappear. Perhaps, since the modem is essentially useless, an alternative module or two could be loaded here for improved functionality at power on? I haven't seen anyone investigate that.
Then finally this looks like the area where the sound components should be added. With SK1 below, which I assume is where a PS2 connector can be fitted.
Now off to stalk ebay for a reasonably priced Zip100 drive, which hopefully hasn't already click-of-deathed.
