ath@lcs.mit.edu (Andrew Heybey) (11/06/90)
In article <1484@sumax.UUCP> davidy@sumax.UUCP (David L. Yee) writes:
I am in need of some help and or information. I just recieved
my GVP Series II hardcard with on-board memory exapansion. This is the new one
with DMA access. Anyway, it refused to operate with the memory installed and
the memory configuration jumpers set appropriately. If I disabled the RAM
jumpers, or removed the RAM entirely, the card booted and runs fine.
Needless to say, I was a little perturbed, so I called up GVP today
(11-2-90, 1:30 PST) and asked to see what was up. A person named Gary took my
call. What he told we was this:
I have a rev 4.3 motherboard. Gary said that Commodore made a
number of 4.3 motherboards without a certain resistor. This
resistor is a 470 ohm, 1/4 watt resistor that (I believe) he said
was supposed to be connected to the DTACK line of the 68000 (My
memory on the DTACK portion is a little hazy, the rest is not.)
Anyway, here is approximately where it should go:
[Diagram deleted].
I had exactly the same problem. However, the person I spoke to at GVP
told me to install the resister at a silkscreened location just to the
right and behind the power connector. I can't remember the resistor
number right now, but it was four digits :-). The location next to
the power connector is a lot easier to get to with a soldering iron
than the location next to the 68000.
Anyhow, I tacked in a resistor this weekend, and now everything works
just fine. I ran a memory test overnight and found no errors.
Since I have caused them so much trouble, I thought that I would plug
the company from which I bought the RAM. When the SIMMs didn't work
in my board, I first called GVP, who said that they had experienced
problems with "cheap SIMMs" not working. I then assumed that it was
the SIMMs that didn't work. TechnologyWorks sent me 4M of
replacements via overnight mail at their expense. The new RAM didn't
work either. I called them again, and they sent *another* 4M via
overnight mail at their expense. This last set used chips from
another manuafacturer (the first two were the same), which is when I
decided that the problem must lie elsewhere and called GVP again (so
I'm a little slow). TechnologyWorks *also* paid the postage for me to
return the SIMMs that I thought didn't work.
TechnologyWorks, Austin TX, 800-688-7466, $49 each 1Mx8 SIMMs
--
Andrew Heybey, ath@ptt.lcs.mit.edu, uunet!ptt.lcs.mit.edu!ath