View Full Version : Another Unkown Card ?

Micom 2000
May 24th, 2006, 04:31 PM
While working on resussicating an old IBM PC 5150 I discovered that what was used as a memory card to increase its memory to the 640 DOS limit with 8 banks x9 64k-15 chips also had a slot in the mounting plate to accommodate a ribbon cable which had been taped over with masking tape, hence unused. There were 2 similar mounted sockets only one of which had an 8250 UART.
There are 3 26pin sockets on the card and another 16pin one leading to the slot. It has what appears to be a battery labelled Datatronic and 2 4pin connectors like many com connectors on the upper corner labeled J2 and J3. I would guess some sort of serial connectors with the 16pin one (it's plastic casing is blue) acting as a controller.
The only visible identification is an STB logo and the sn# is inked over with "3190".

Could this be some sort of early multiple modem thing ?
Or did it have some other function unrelated to the UART ?

Would like to know it's other capabilities besides memory.


Terry Yager
May 24th, 2006, 04:49 PM
Prob'ly a 'multi-function' board, incorporating memory expansion, parallel port, (2x) serial ports (the 8250 supports 2x 8-bit input & 2 output, IIRC), and (usually) an RTC.


Micom 2000
May 24th, 2006, 05:47 PM
Yeah a muti-function board like many of them but without the usual parallel or serial connector on the mounting plate. These are 3 26-pin connectors and a 16pin (blue) one on the card lined up leading to a slot on the face plate. What would you hook up to them.
I'm wondering if it could have been some sort of multiple modem or early LAN additional function. What used 26pin or 16pin connectors ? A "Sync" array for the 5150 ? The memory configuration tends to pin it to the PC or XT. Coms only needed 4 at that time altho they used the DB9 connector. There is also a pod of miro-swiches on it for configuration.