Non-Working 5170 System Board

[pcdata76]

I found a 256/512 kB system board of 5170 with 128k piggybacked memory on a local auction website. I requested from owner to check the board by connecting an ISA video adapter and AT power supply. He did, but said that he couldn't get a video. The board has one missing memory chip on Bank1 (second) but in this case it should throw a parity error if i'm correct. Btw, i have few questions about the board since i didn't own and used a 5170 and i have a limited knowledge about these boards.
1- Does 5170 board post with missing/faulty chips on Bank 1?
2- Can i use 4164 chips instead of 128k piggybacked chips (with reduced system memory of course) if i replace all 128k chips with 64k ones in a bank?
3- Can i diagnose the board using a POST card? Does it throw a code to the post card even if there is a faulty memory chip on Bank 0 or POST card is simply useless on 5170s too as in the case with 5150?
4- Does a 8-bit conventional memory expansion card like AST 6pakplus work on 5170 or i need 16-bit memory expansion card?

 

[SpidersWeb]

There's another thread in this forum currently discussing replacement RAM for the 5170, I'd recommend checking that out.

I'm personally not an expert on what's possible, but I did want to confirm that I've used 8 bit memory cards in a 5170 to fill the gap between 512KB and 640KB - both a generic card and an actual AST Six Pack Plus - however I did notice it was slower when using that area and I haven't tried mapping it below a 512 start point.

There were many 286 designed cards that gave XMS or EMS that were also able to backfill the conventional too. If you can find/snag one of these that's even better.

 

[modem7]

Lots of IBM 5170 information at www.minuszerodegrees.net

1- Does 5170 board post with missing/faulty chips on Bank 1?

Yes, providing that bank 0 is working. A "201" type memory error will be seen.

2- Can i use 4164 chips instead of 128k piggybacked chips (with reduced system memory of course) if i replace all 128k chips with 64k ones in a bank?

No.

3- Can i diagnose the board using a POST card?

Yes. The POST codes generated by the 5170 motherboard are listed in the 'IBM AT BIOS' section of the web page at [here].

Does it throw a code to the post card even if there is a faulty memory chip on Bank 0 ...

Yes. See [here].

4- Does a 8-bit conventional memory expansion card like AST 6pakplus work on 5170 ...

* Slower operation, because two 8-bit transfers are required instead on one 16-bit transfer.
* The ISA bus on the 5170 is run 'faster' than that on the 5150/5160. Therefore, some 5150/5160 boards may be unstable.

 

[pcdata76]

Thank you for answers. Then, i'll buy the board if seller gives me cheap.

 

[modem7]

Thank you for answers. Then, i'll buy the board if seller gives me cheap.

Of course, you are taking a gamble. A 'dead motherboard' symptom can have many causes. And if the cause is not RAM, a POST card might not display anything at all. And if the POST card does display something and then stop at a particular code, that code may 'point the finger' at many motherboard chips.


Mandated government notice: Please gamble responsibly.

 

[pcdata76]

For sure. i wont buy if seller wants more than its scrap value.