Re: Extended 80 column card issue

[dempson@actrix.gen.nz (David Empson)]

Jeff Shanholtz <jeffsubs@shanholtz.com> wrote:

> I bought an untested Extended 80 column card on ebay so I can get 128k
> memory in my IIe. A gamble that I lost. Ha ha. But it was cheap and
> pretty simple as far as the circuitry goes. Anyone know what typically
> fails on these cards? I tried booting the Apple IIe diagnostics disk
> from asimov (A2eDiagnostics_v2.1.dsk) and it reports "no extended 80
> column card" (same as it does if I leave my regular 80 column card
> in). That is what leads me to believe the card is not functioning. I
> haven't seen any other symptoms caused by this card, although I didn't
> leave it in for long either.
> 
> I've got an arcade game that uses 4164 ram (I understand 4164 and 4264
> are compatible) so I can start swapping ram chips in if the ram itself
> is the first place to start, but there's also a pair of logic chips.
> So if one of the logic chips typically goes out then I'll start there.
> 
> Also there's a jumper on the board that's closed. I'm assuming that
> wouldn't cause a problem but throwing it out there just in case.

If it is a genuine Apple card, the early models were designed for use
with a rev A or rev B IIe.

I'm hazy on the details, but if memory serves, rev A didn't support
Double Hi-Res graphics, and the jumper needs to be set correctly for the
model you are using, or DHR won't work in a rev B and strange things
will happen in a rev A.

-- 
David Empson
dempson@actrix.gen.nz