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

[IUnknown <stevementzer@gmail.com>]

On Oct 18, 2:47 am, demp...@actrix.gen.nz (David Empson) wrote:
> IUnknown <stevement...@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
> demp...@actrix.gen.nz

The card is the 820-0166-B.

It has 256k soldered in, three banks of RAM chips socketed and two
jumpers on the board, both of which are closed.

The board installs and recognizes the memory in the system control
panel (RAM disk...) of my ROM01.   The ROM3 just doesn't see
anything.

I tried tensioning the spring connectors on the memory expansion
slot... sprayed some contact cleaner, etc to no avail.

This one has me stumped. I am starting to think that there is
something hardware related going on w/ the ROM03.

The one difference between the rom01 and rom03 is that the pram
battery is dead on the ROM03. Not sure why that would make a
difference though....

Thanks!