[net.micro] S-100 / IEEE 696 then and now

russ (03/24/83)

#R:cwruecmp:-54600:hp-cvd:7100002:000:1219
hp-cvd!russ    Mar 22 08:56:00 1983

You probably could use an old IMSAI or ALTAIR, but don't expect much.
The motherboard is certainly not shielded or terminated, and they're
generally not reliable for business use.  Of course, they're probably
just fine for hobbyist (sp?) use.

This caution does not apply to the Ithaca Intersystems computer.  This
computer is obviously an IMSAI, redone correctly.  The power supply uses
cables, not a pc board, the power switch is mounted on the chassis, not
the front panel, etc. etc.

IMSAI/Altair front panel compatible implies that the CPU has a sixteen
pin header plug for a cable running from the front panel.  Only eight
signals are used; the other eight are ground (except on the Intersystems)
These signals come straight from the cpu's data pins.  On the IMSAI, the
LEDs are driven straight from the signals, no buffering!  And the same
goes for the address bus LEDs!

The front panel also requires some other funny signals, such as XMEM*,
to be on the bus.  I don't know if IEEE-696 supports those signals.

I don't know exactly what is reasonable for a power supply.  If you try
to dissipate more than ten watts per S-100 card, you're just asking
for trouble.

					Russ Nelson
					...hp-pcd!hp-cvd!russ