27 Jan
2009
27 Jan
'09
1:06 p.m.
The best s-100 memory cards will use static memory cards ... the chips will
be 2102's (for very old 4k and 8k cards), 4044's, 2114's, 2147's or a few
others for 16K and 32k cards or 6116's for 64k cards (some of these chips
had other numbers for what were, essentially, the same chip). The best
cards are the Godbout / CompuPro cards, which I believe were all static, but
quite a few other static memory cards were good also.
There are SOME good dynamic cards, I've had excellent success with Cromemco
16KZs, and with the SD Sales Expandoram cards. The problem is that it's
hard to know which dynamic cards are good vs. which ones are bad (and the
bad are very bad indeed), and there can be a lot of compatibility problems
with front panels and DMA. So I prefer to avoid them, but a few of them are
ok.
-----Original Message-----
From: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org]On Behalf Of Josh Dersch
Sent: Tuesday, January 27, 2009 1:46 AM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Recommendations for IMSAI-compatible RAM cards?
Hey all --
Acquired an IMSAI 8080 in half-assembled condition (but the price was
right). I believe that (after doing some thorough cleaning, debugging,
and replacing of old cabling) that I've got the front panel and CPU
functioning correctly. However, the IMSAI came without any RAM cards so
I'm unable to go any further at the moment.
I have one S-100 RAM card but I have no documentation on it and it's
missing a couple of ICs (and what they're supposed to be, I don't
know). It's a PSS RAM65. My internet searches for info confirm that
the card does indeed exist, but I can find no technical information.
From my research, my understanding is that S-100 RAM cards are fickle
and compatibility with front-panel machines can be an issue. Does
anyone have any recommendations for what to look out for as I begin my
search? Anyone have any decent RAM cards they'd be willing to part with?