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The Great Extendo

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stepleton:
These AppleNet cards are making a monkey out of me. I'm gonna need to probe them, but it's hard to reach them inside the Lisa when they are installed.

Does anyone have any physical specifications or measurements for Lisa expansion cards?

I'm thinking it might be nice to make some kind of bus extender. I would be shocked if you could still get those ZIF expansion slots from anywhere, but maybe it's possible to hack an ordinary card-edge connector to receive a Lisa expansion card. Anyway, the idea would be to feed the bus lines just a short way outside the case via ribbon cable---that way I can poke the card with a scope. I'm not sure how much the bus will tolerate this, but it's not too much of a hassle to give it a shot.

Speaking of things around the expansion connector, has anyone got a source for those wide-slot screws that the rear panel uses to hold in the expansion slot cover plates? I'm missing one.

rayarachelian:
The specs are in the Lisa Hardware Guide for the size of the cards, etc. don't have that handy now, but check bitsavers
I think the pins are the same spacing as IBM PC ISA slots, so if you can find a connector for an 8 bit ISA slot - the short ones, you might e be able to use that, though youll need to cut the back end so the card can slide into it as the lisa card is much longer and expects to slide in as those zif sockets are pretty unobtainum.

I don't know if isa slots are still available, but I'd guess they're a lot more available than lisa ones. worst case you've got a lot desoldering to do to reclaim one off a dead motehrboard.

(still no electricity)

patrick:

--- Quote from: stepleton on August 06, 2020, 07:03:50 pm ---Does anyone have any physical specifications or measurements for Lisa expansion cards?

--- End quote ---

Attached is a template for the Lisa Expansion card in Eagle 2.60 and 5.12 format. KiCAD should be able to import this.

Some 20 years ago I made my own SCSI card for MacWorks. Based on the SunRem circuit, two-layer PCB etched in the kitchen, all components soldered from both sides, no plated slot -- but it worked! A few years later it got replaced by a genuine SunRem board after a couple of unpopulated bareboards appeared at ebay.

stepleton:
Fantastic! Thanks Patrick!

Guess this means I've got to go ahead and try to make one of these things  :D

patrick:
How do you want to arrange the board unter test on the extender? 90° rotated, so that it points out backwards?

Provide a breakout point (pinheader with jumpers) on each signal line, and one test pin for the logic analyzer. Or better two, one before and one after the break. And many Gnd connections. Power lines might be protected with PTC (self-restoring) fuses and fitted with indicator LEDs.

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