Compaq Portable III / Portable 386 Expansion board Bracket

thingiverse

This is a bracket and cover so that you can make your own Expansion chassis for the Compaq Portable III and presumably Portable 386 computer. The Expansion chassis is very difficult to find. I found a pinout for the connectors here: https://forum.classic-computing.de/forum/index.php?thread/16680-compaq-portable-ii-und-compaq-portable-386-expansion-unit-schaltplan-und-connect/ The KiCad schematic is what you need. I did not build mine with the 74LS125 buffers. The buffers would be needed if you have cards that use the 8 Bit memory space. You will need a 16 bit ISA slot connector (62 + 36 pins) and a 96 DIN connector. I had some from an older system and don't have part numbers. I simply wire-wrapped all of the connections. I added a single M2 screw in the middle of the ISA connector to help locate it. It was designed to be friction fit, but needed just a little more strength. I was able to get an NE2000 Ethernet card to work well with this adapter. Other ISA cards should work. Update 2022-06: Added the housing to cover the back of the chassis. This is sufficiently sized for a 'short' card. Probably not long enough for a full-length ISA card. You will need to drill the holes for screws to attach to the connector bracket as well as for the ISA card 'ear' connection. I had to sand down the clips that go into the compaq chassis to make them fit well.