Altair parts substitutions

From: Cini, Richard <RCini_at_congressfinancial.com>
Date: Mon May 22 11:05:55 2000

It's that time of year again, when I think about designing an Altair/IMSAI
work-alike. Now that I have the ability to generate schematics/layouts, I
may actually try it.

Anyway, some parts have become scarce, so I would have to use substitutes.
For example, Jameco no longer carries the 8T97 buffer/driver. As I recall
the 8T97 is an LS373 without the inverter on the gate *and* is faster and
has a higher drive current. I've heard that the MC6887 is a sub, but I can't
find a datasheet on it.

The 8101 dual-port 256bx4 RAM is no longer available, but Jameco has a 5101
which looks like a likely sub. I would forego this type for a larger SRAM,
but I guess that it too would have to be dual-ported. I need to look at the
schematics for an S100 memory board.

Someone on-list did a design for his own clone, but I can't remember who it
is. I'm sure that it can be done cheaper than Tom Fischer's IMSAI-2 though.


Rich
Received on Mon May 22 2000 - 11:05:55 BST