7 Nov
2014
7 Nov
'14
9:42 p.m.
What are the main ICs on the board (basically anything other than TTL, 4000
series CMOS or common op-amps)?
The CPU is an RCA 1802, there's a CDP1852 which is a parallel I/O port IC,
RAM is a pair of 2114's, and a 24-pin IC which has a sticker on top saying
(unhelpfully) "IC-584" (but I expect it's ROM).
Finally we have a 22 pin IC labeled "SC-01-A" - Google tells me that's the
actual speech synthesizer IC. The remaining ICs on the board are all
simple logic (74xx etc.)
The SC01 is a well-known Votrax speech synthesiser IC. I am sure you can
find a data sheet somewhere (I have it, I think, but my stuff is still packed after
the move!).
A 24 pin ROM is not going to be more than 8K (It would be useful to know how big
it is). You _might_ get text-to-speech in that.
With no UART, I guess it bit-bangs the serial protocol (I am surprised there's no
CDP1854 on the board). Pity. If there was a UART you could stick a 'scope on the
baud clock input and find out what bit rate to use.
-tony