> > time I try out things, I'm going to split the Warrior
> > data up among some 2716s and plug it into a Star Castle
> > motherboard!
>
> Well, if splitting them will work, then plugging the 2532s in the rev K board
> should work as well, right? (the proof is in your description of RO and SC
> above) Save yourself some time and try the 2532s directly
You are correct. If splitting them would work then using the 2532 would too.
> The discussion about the 2532s got me thinking, though. If I have a daughter
> board that is generating the A12 signal, and the appropriate CE signals for
> the odd/even banks, why not combine all the EPROMs onto a single 27128? CE
> can always be high, and the old CE signal can be used to select the
> appropriate bank. If you want to extend it further, in the 4 game hack, put
> all the images on a single 27512, with all the selection lines coming from the
> daughter board. Certainly a lot cleaner than having 4 wire wrap sockets
> crammed into the original sockets. All it would take is one 2716->27512
> adapter in U7, with 4 wires coming from the daughter board, with a 2 position
[..]
> Comments before I spend a lot of time on this? (Unfortunately, I have to
You can't put them all into 1 chip.You can put them all in 2. The board
selects 1 odd and 1 even ROM at the same time (or nearly same). It latches
the data from one (odd I think) for later use. It's like a 16 bit data bus
to make up for the SLOW EPROMs of the time. Keep in mind that it runs at
1.66 MIPS (or higher?) so it needs to grab data fast.
I suppose you could use 1 large ROM but you'd have to figure out how the
sequencer works AND run A0 up to the EPROM, since it is normally used to
select even or odd addresses. The sequencer has it's own microcode prom
that not even I have looked at much. This is different from the 4 small
microcode ROMs that produce all the processor control signals which I do
understand in great detail (yes steve I'll get writing). Anyway you'd have
to understand how the sequencer works and be able to reprogram it for only
1 rom... More work than just using 2 eproms. They do make 16bit-wide eproms.
BTW it really is 1.66 MIPS. People go nuts when you tell 'em its all TTL.
-- ___ __ _ _ _ | \ / \ | | | || | Engineer/Programmer | _/| || || |_| || |__ " What makes someone care so much? |_| |_||_| \___/ |____) for things another man can just ignore. " -S.H.
