Re: IIgs RAM Card Identification

["Polymorph" <polymorph69@hotmail.com>]

Ed Eastman wrote:
> Polymorph wrote:
> > Here's what I have found by trial and error:
> > * When no jumpers are installed the card is inactive (no expansion RAM
> > detected)
> > * When jumper 1 is on only, the card reports 768K being installed
>
> This means that it tells the IIgs it has 512k.  With the 256 on the IIgs
> main board itself, this makes sense.

The 768K I mentioned was calculated taking into account the motherboard
memory, in my case 1Mb as it is a ROM03.  What IS weird is that I tried
the same configuration on my ROM01, and it displays 640K as being
installed.

>
> > * When both jumpers are on, the card reports 1Mb being installed
>
> Jumper 2 must be for the 2nd 512k for a total of 1024 (+main board ram.)
>

I agree, but I don't have enough RAM chips to take it to the full 1Mb
to test (as the first 256K are soldered onto my Apple branded card).
The card definatetly reports 1Mb when both jumpers are on.

> >
> > So taking this information, I loaded the card with 768K, put jumper 1
> > on, and ran the GS Memory Diagnostics. It seemed to go through pass one
> > of the test (ie. it did the countdown thing OK), but bad RAM was then
> > detected.
>
> It was probably 'confused' by the extra 265k you put on the card.

I'm pretty sure I tested with only 512K installed as well, and it
failed the tests also. If I get time, I might retry this test to
confirm.

>
> > If nobody's got any idea's, I'll probably shelve this card until I can
> > figure out what to do with it.
>
> Further testing should prove or disprove my thoughts...  Good luck.

I'm pretty confident that I've tried all sane combinations of jumpers
vs RAM installed. I even tried placing RAM in different bank orders.
Interestingly, when I placed 256K in bank 3 alone with no jumper
installed, 256K was reported. However, the RAM test failed as before.

This card has been shelved for now, until I get the time to do more
investigation/testing, or someone can enlighten me to why I am seeing
this strange behaviour.

Thanks for your input though.

cheers,
-p