Altair parts and the like

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Tue May 23 11:28:18 2000

> Thanks for the 8T97 offer. My goal for this project would be to make for
> myself an 8080-based SBC using modern parts and having some sort of front
> panel. I have no illusions of reproducing an Altair or IMSAI.

The real work of making a SBC with front pannel is literally the front
pannel. There are a lot of switches, leds and drivers required. A
software front pannel like the H8 is far less hardware.

Also you don't need the old parts if you not building an ALTAIR/IMSAI at
the schematically identical level. If you want functionally identical
and still S100 then 74HCT or even 74LS parts of late origin are a better
bet. From the block diagram level it makes little difference if a buffer
is 1/6th of a 8t97 or 1/8th of a 74hct244. Same applies to the latches
used. Using the octal vs hex parts will save a few chips.

Also as a point I"d do the IMSAI as the altair design was bad on a good
day. Too many oneshots and the FP connected to the bus via a bundle of
wires (some over a foot long) making the bus noise worse. IMSAI was
design with the front pannel plugging into a S100 slot directly and was
cheaper, cleaner and more reliable as a result.

Allison
Received on Tue May 23 2000 - 11:28:18 BST