Re: IIgs RAM Card Identification

["Bill Garber" <willy46pa@comcast.net>]

"Polymorph" <polymorph69@hotmail.com> wrote in message
1158025009.522612.114140@i42g2000cwa.googlegroups.com">news:1158025009.522612.114140@i42g2000cwa.googlegroups.com...
:
: Ed Eastman wrote:
: > Polymorph wrote:
: > > Hi Ed,
: > >
: > >> I notes from the scans that it looks like the banks may be arranged
: > >> vertically.
: > >
: > > Really?? That is definately one thing I didn't try. I interpreted the
: > > writing on the front side of the card to mean that it had the same
bank
: > > arrangement as the Apple branded card
: >
: > Well it seems odd, but tha's just the way it looks to me.  I have not
: > traced the wires and could be totally incorrect.  But go ahead and try
: > placing 16 chips towards the east or west end and see what happens.
: >
: > > You are very gracious in your offer, but unfortunately I am located in
: > > Australia, so postage costs may be an issue.
: >
: > 8 chips to Australia is a time consideration, not a cost...  Postage
: > would only be $10 or so considering how light they are...  (Not really
: > willing to overnight them for the cost.)
: >
: > Thankx,
: > Ed
:
: Thanks Ed, I'll give it a go and post my results.
:
: So just to clarify, if I were to load the chips in a vertical
: arrangement would be like the following:
:
: 256K:
:  XXXX OOOO OOOO OOOO
:  XXXX OOOO OOOO OOOO
:
: 512K:
:  XXXX XXXX OOOO OOOO
:  XXXX XXXX OOOO OOOO
:
: where -  X = DRAM installed;   O = Empty
:
: cheers,
: -p


This should be exactly like the Apple card.
With Bank 1 filled, 8 - 41256 (256kx1) ram
chips, and no jumpers installed, you should
get 256K. With banks 1 and 2 filled, you need
jumper 1 installed to get 512K. With Banks
1, 2, and 3 filled, jumper 1 on, jumper 2
off, you get 768K and with all of the Banks
filled, both jumpers on, you get the full 1 MB.
Fill the card, then experiment with the jumpers.
You can't hurt it. All they do it change the
state of CROW0 (jumper 1), and CROW1 (Jumper 2).

Bill Garber
Owner - Garberstreet Enterprizez
Co-owner - GSE-Reactive.com
(610)935-7676 (610)329-8996