#HELP!!! A-500 Weird Agnu
7 messages in this thread
O.K. So, I bought a used A-500 with an 8372-A Fat Agnus chip. But the
motherboard has not been modified to address 1 MEG of Chip Ram.
However, all the docs and info I can find do not match the motherboard I have.
There is no REV # anywhere on this board. The JP2 solder pads are not located
between the 68000 and the ROM. They are located next to Gary, and there are
only two pads, not three.
What in the world do I have. Can it be modified? Who ya gonna call???
Any clues…drop me an E-Mail.
Thanks,
Reggie Hall
Ouch. Sounds like you may have a rev. 3 (or maybe even earlier?) Seems like
the previous owner thought that if he put in the 1 Meg Agnus chip, he would
automatically have 1MB chip ram…that's what I thought at once 8) But anyway,
all my docs say that if I had earlier than revision 5, it would be pert near
impossible for me to make the upgrade. Just my 2 cents…
Kevin,
Thanks very much for your reply. Everyone seems to agree with you. I'm
looking at buying another machine and keeping this one for parts.
If it were not for this excellent forum, I would be completely lost!
Thanks again,
Reggie
For the revision # check over by the disk drive under the Rock Lobster Logo.
Also the fat agnus needs a baterry back up clock with it's i/2 meg ram.
everybody out there correct me if I'm wrong and add more detail to this.
. RAL *Amiga was my first* // //
. What I cannot do alone We can do together \\// \\//
RAL,
People are telling me that this board may be too early and/or too difficult to
modify. Revision three or earlier. But I sure do appreciate your reply.
If it were not for this excellent forum, I would be completely lost!
Thanks again!
Reggie
That's a rev 3 machine. I don't believe it was ever sold in the US,
officially at least. Some of the mail order outfits were selling the bare
boards before CBM died. I got one for spare parts at a HAM radio swap
meet. The revision level is on the solder side of the board, underneath
where the floppy sets… almost exactly under where the assy # is on the
top side. I don't know the mods for this revision, though. It's not in my
A500 schematics.
-Jim
MOS via Autopilot & Amiga
Jim,
Thanks very much for your reply. Everyone seems to agree with you. I think
I'm going to buy another machine and just keep this one as a spare.
If it were not for this excellent forum, I would be completely lost!
Thanks again!
Reggie