Re: IIgs ROM3 w/ 1MB RAM Board - Issue....

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

IUnknown <stevementzer@gmail.com> wrote:

> Situation:
> 
> I have a ROM3 IIgs with a fully-populated 1MB apple RAM board. The
> board recognizes just fine in a ROM01, but not in the ROM03. There is
> no additional memory shown in the system control panel.
> 
> Anyone run into this issue before?

Some early IIgs memory expansion cards tried to fully decode the bank
address from the bus rather than using the row select signals on the
slot, and this resulted in them not working properly in a ROM 3 IIgs,
nor with DMA from an Apple High-Speed SCSI card.

Is this a genuine Apple card? If so, what part numbers can you see on
it, and what does it have in the way of socketed vs soldered RAM chips?
I seem to recall some issue with variants of Apple's 1 MB IIgs memory
expansion card.

I'm aware of three IIgs memory expansion cards that Apple made.

In the US, they had a card which came with 256 MB soldered which could
be expanded to 1 MB via socketed chips. It used jumpers to indicate how
many banks were active.

In Australia and New Zealand, they sold two different cards: a short
card with 256 MB soldered, and a long card with 1 MB soldered. Neither
card had any jumpers.

I may still have my 256 MB card buried in a box somewhere. I never had
the 1 MB card, unless I've inherited one from other people donating
unwanted parts and/or computers.

-- 
David Empson
dempson@actrix.gen.nz