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Re: [N8VEM-S100:1957] Programming GAL's

On 10/9/2013 9:19 AM, monahanz wrote:
Guys I'm thinking of extending out 8088, 8086, 80286 and 80386 line of
S-100 boards to include a 80486 board. The 80386 board was a major
hurdle for us hardware wise. The prototype and daughter RAM boards
design now feel fairly sound and should be available over the next few

While the 80486 would appear a small further hardware leap from the
80386 (and it is for 32 bit data), unfortunately Intel in their wisdom
decided to handle 16 bit (and now 8 bit) data transfers differently to
that on the 80386. Now the upper 16 or 8 byte/words and NOT shifted down
to the lower data lines for 16 and 8 bit data transfers.  You have to
use external latches/buffers. This mounts to probably more 754LSXX IC's
that a single board can accommodate.  I think I could squeeze things
using a few GAL's to eliminate a number of chips.

For programming them I would prefer not to use a high level language
(the logic is simple, few chips).  I was thinking of using something
like PALASM. Could somebody direct me to a DOS/Windows version that I
could get a run-time version.  I see many references/write-ups but no
actual run-time code.

BTW, with such an 80486 board even old 8 bit S-100 boards would be
usable!  (Like sticking a Lamborghini engine in a Volkswagen!).


PALASM is a DOS only thing. I've used it recently with DOSBox version 0.74 under windoze and it worked fine for a retro Heathkit H89 re-spin.

I think I used the PALASM version from:


I'm suspicious that you might not find PLD parts with 16 inputs - if you want to build a 0/8/16-bit shifter.

Atmel makes some bigger CPLDs and they have a version on WinCUPL that might be interesting.