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pjh
January 27th, 2016, 12:01 PM
I need help identifying an unknown serial card I just won on eBay. If I can identify the maker I might be able to get the manual for the card. There is a small 'sunrise' logo in the lower center of the card with 49-82 under it. A preliminary search for any 'SUN' related classic suppliers (Sun Microsystems, Suntronics, etc.) didn't turn up anything.
Any help would be appreciated.

Phillip


2927129272

glitch
January 27th, 2016, 12:09 PM
I believe the little sun logo is from the board shop that actually produced the etch of the board. I'm guessing "49 - 82" is a manufacture date. There were a lot of one-off, no name S-100 boards produced by system integrators, especially for industrial control stuff, in the early to mid 80's. Documentation will probably be hard/impossible to find. I've got several boards in the same situation.

The good news is, there's not much to that one. Looks like it's two Motorola 6850 ACIAs and the associated Motorola baud rate generator, plus a bit of glue logic to put it on the bus. You can probably make it look like a MITS 2SIO. With all that prototype area, you could also cut the chip enable lines and do something custom, too.

pjh
January 27th, 2016, 12:25 PM
Thanks for the quick reply. You are right. The board schematic should be easy to figure out. I have already downloaded the 6850 pages from 'An Introduction To Microcomputers Vol.2' to figure out how to initialize the ACIAs. And I have already got the 'board select' part of the circuit figured out. More to do.

Phillip

glitch
January 27th, 2016, 12:32 PM
One bit that's a little concerning is the lack of bus transceivers -- I only see one 8-bit transceiver. Perhaps I'm just missing it though.

pjh
January 27th, 2016, 01:03 PM
You're not missing anything. It's just missing. One thing I do to begin studying a card is to find out which S-100 buss pins are being used. This card has traces from the DO0-DO7 pins but there are no traces from the DI0-DI7 pins.

glitch
January 27th, 2016, 01:12 PM
You're not missing anything. It's just missing. One thing I do to begin studying a card is to find out which S-100 buss pins are being used. This card has traces from the DO0-DO7 pins but there are no traces from the DI0-DI7 pins.

Interesting -- I'd guess it was either used on an IEEE-696 system (16-bit bidirectional data on the DI and DO buses), or it was a sort of "write only" serial port, for controlling something where it didn't need feedback. Not sure how you'd manage to check to see if the 6850 ACIA's transmit buffer was clear, though.

Looks like your prototype area is limited to 16-pin DIPs without cutting traces. You could use a pair of 74LS367 (or compatible, there were a bunch of part numbers) to drive the DI bus. You'd need to wire up bus transceiver select logic for it.

pjh
January 27th, 2016, 02:14 PM
Interesting -- I'd guess it was either used on an IEEE-696 system (16-bit bidirectional data on the DI and DO buses), or it was a sort of "write only" serial port, for controlling something where it didn't need feedback. Not sure how you'd manage to check to see if the 6850 ACIA's transmit buffer was clear, though.

Looks like your prototype area is limited to 16-pin DIPs without cutting traces. You could use a pair of 74LS367 (or compatible, there were a bunch of part numbers) to drive the DI bus. You'd need to wire up bus transceiver select logic for it.

Sounds like the direction I will have to go if I want to use the card in my system.