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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: guruofgent on February 09, 2008, 10:14:53 PM

Title: bad expansion board?
Post by: guruofgent on February 09, 2008, 10:14:53 PM

I'm brand new to Amiga-type hardware, so don't know a lot about what I'm doing.  I just got an Amiga 2500 for free.  Powering it on, I see a System Expansion Board Check table telling me the board with Manufacturer 1856 and Product 18 is bad.
I have no idea which board that is - didn't expect much for free, but I'm thinking I could pull out the bad board and see what this computer can do.  Any idea where to look to find out which board this is?

Title: Re: bad expansion board?
Post by: zipper on February 11, 2008, 02:25:25 PM

Quote

.  Powering it on, I see a System Expansion Board Check table telling me the board with Manufacturer 1856 and Product 18 is bad.
 Any idea where to look to find out which board this is?

Are you sure? Boards.library doesn't recognize that ID (at least my version). But for example Supra is 1056.

Title: Re: bad expansion board?
Post by: DaBest on February 11, 2008, 02:59:12 PM

"I see a System Expansion Board Check table telling me the board with Manufacturer 1856 and Product 18 is bad."

I dont remember seeing that either when I had my 2000.

weird.....
 :-?  :-?  :-?

Title: Re: bad expansion board?
Post by: banzai on February 12, 2008, 01:58:08 PM

Are you positive that's "1856/18" and not "1056/10"? The default font for Amigas use a slashed zero.

If it is, then you've got a Supra (Manu # 1056) RAM (Prod # 10) board in there. It'll be a full-length Zorro-II board, with either a couple of rows of chips, or an entire armada of 'em. The most common problems with this guy:

Bad RAM -> This board uses 1Mx1 DRAMs, set for banks of 2M (0MB, 2MB, 4MB, 6MB, or 8MB). A fully populated board will have 64 chips (plus logic/buffers). You'll need to set the jumper to "Test" mode and run the Supra RAM Test program to ID the bad chip (it'll tell you the column/row of the culprit).

Jumper mis-set -> Setting the jumper to 4MB when you only have 2MB won't work. Count the rows of chips to get the MB count, and set the jumpers accordingly.

Gunk -> Sometimes, just re-seating the card will clean up any corrosion or gunk on the contacts. Can't hurt.

Conflict -> Do you have any cards (like a BridgeBoard) that are also mapped into the 8MB auto-config area? If so, set the Supra to 6MB or less to have it auto-map the RAM around the other board to check.

Check those, and get back to us ;)

banzai

Title: Re: bad expansion board?
Post by: guruofgent on February 13, 2008, 05:08:00 PM

You are right, it is a Supra RAM board.  Good call.  Whenever I get a keyboard/mouse to hook up to this thing I'll check out all your suggestions.
Thanks.