Designing building fabricating an Apple 2+ peripheral I/O expansion card
So you want to design and build your own custom Apple 2+ peripheral card. You have access to a schematic capture and layout software, so what you need are the details. Its always the details. I have two vintage Apple II+ I/O expansion cards, which with a set of rulers and calipers, can make all the details available to you.
PROM Blaster Peripheral Card
This expansion card was for burning UVEPPROMs. Card Width: 6.5 inches Card Height: 2.75 inches (not counting finger contact area) Card Thickness: 69 mils Finger contact area width: 2.6 inches Finger contact area height: 300 mils Finger contact area offset from edge: 3/8 inch Individual contact width: 70 mils (hard to measure) Component Heights: typical 360 mils but socket is 460 mils
Z80 soft card peripheral card
This expansion card gave you a Z80 processor Card Width: 7.25 inches Card Height: 2 11/16 inches (not counting finger contact area) Card Thickness: 63 mils Finger contact area width: 2.6 inches Finger contact area height: 280 mils to 315 mils (its not the same on each side?) Finger contact area offset from edge: 3/8 inch Individual contact width: 50 mils (hard to measure) Component Heights: typical 320 mils although LED is 490 mils tall
Double checking the information by looking up mating connectors.
So these cards may bottom out, or not depending on the connector.
Recommended Contact Width: Sullins: I did not see one specified. EDAC: .055" Hirose: 1.6mm+/-0.1mm = .063+/-.004
Connector slot width for 25/50 contacts: Sullins: 2.6"+/-.008" (did not see recommendation) EDAC: 2.6"+.010-.006" (they recommend 2.6" - .012 to .016) Hirose: 66.04mm or 2.6" (they recommend card finger width 65.94 or 2.596") This dimension is very tight. Its possible your card may not fit, as there may not be positive clearance.
It would appear that the dimensions are not an exact science so as long as you are in the ballpark of the numbers given above, you should be fine.
Motherboard / Expansion Card I/O pinouts
The Apple 2+ expansion card connectors are pin numbered per the picture above. Pins 1-25 are on the top side of the card. With pin 1 towards the card middle, and pin 25 near the card edge. The silkscreen has the "1" and "25" labeled on the old card. Just be aware that most companies do not label the edge connector in the particular order that the old Apple 2+ does.