So I'm reading on the Raspberry Pi project, and it seems to have some desirable features:
1) Runs a full Linux stack
2) Costs USD 25 when it finally releases
3) has about sixteen digital I/O lines
I'd think 1) would give you a lot of flexibility, and 2) makes it cost-competitive with an Aikon-style job, but 3) might be a bit short for the job. The regular AIKON has 26 I/O lines to the keyboard matrix, no?
I could see some sort of breakout box to address the rows and columns on a subset of the 16 GPIOs, but that would make programming more complex and reduce the cute and tidy factor.
OTOH, it might also be awesome built into a keyboard in a C64 style-- either use the board directly as a computer, or use it to emulate USB devices
Maybe one line for a "Row enable", one for "Column enable", and four lines fed to two demultiplexers (one for columns, one for rows) to give a 16x16 matrix on a six wire bus, but my CS110 is a bit faded...