Uncreative Labs

Guest

This unit has an unusual upgrade installed, it has what looks to be a standard machine socket for an 8088 but instead of an 8088 this unit has a ONE/D card installed with an
amd d8086-2 8439 JMA & an Intel c8087 l6070022 coprocessor. It also has some logic a 74s08n & NEC UPB8288d the card appears to alter the pinout of the 8086 and reroute pins from the 8087 into the single processor socket.

I am curious if this might work in a standard unit or if this is something really strange. I have never seen a coprocessor mounted with a processor into a STANDARD 40 pin single CPU socket. This might be a way of adding a coprocessor to a single socket unit that couldn't accept one.

Also I bought this for the intel 8087 but HOW do I identify which rev or model it is? I know there were 5mhz (which this one currently operates at) and others that were high speed 8mhz or 10mhz.

Cheers
Ryan

Joined: 21 Dec 2005 Posts: 66

The daughterboard trick was used to add 8087 support to the PCjr, which didn't have a socket for the 8087 on the motherboard.

When you are done with it (if that every comes) I'd love to take a peek at it .. for the PCjr of course. Smile

Guest

The odd part though is that this has an 8086 installed not an 8088, the ram appears to be 8 bit wide for a normal 8088 XT not sure how this would work in an 8088 slot though

Is it possible to rewire an 8086 to run in an 8088? And why would you?