Re: EV-100 POWER ON BOARD

[XURQ03A@prodigy.com ( LEE A HART)]

> Everybody join in and help us decide which pins will provide power and
> common on the EV-100 SYSTEM BUS.

You could pick the same pins that the old S-100 used; purchased breadboards
already have power and ground wiring to these pins. But, S-100 had serious
problems because it assigned too few pins for power and ground. Some cards
would draw several amps, and the voltage drops across the connector pins would
seriously disrupt signal levels. So I would suggest you use at least 4 each,
and preferably more pins for both 12v and ground.

Put the same signals on opposite sides; i.e. 12v on both sides. It is common
for edge connectors to get shorted top-to-bottom by bits of debris falling
into the slot, or by a bent edge connector finger, etc.

> 50-51 top end of connector (if numbering starts at 01)

"Top" is vague in the above sentence. As you say, S-100 cards are not
consistent in how they number pins. You need to be very clear EXACTLY how you
are numbering your pins.

The S-100 card locates its edge connector assymetrically; off to one side so
you can't put the card in its slot backwards. Which side is the small
dimension in your illustration? The pin 1 end, or pin 50 end?

Are pins 1-50 on the top (component) side of the board, or bottom
(non-component) side of the board?

Lee Hart                     If you would not be forgotten
4209 France Ave. N.          Soon as you are dead and rotten
Robbinsdale, MN 55422 USA    Either write things worth the reading
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e-mail XURQ03A@prodigy.com   (Ben Franklin, Poor Richard's Almanac)