Re: IIgs RAM Card Identification

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

"Sean Fahey" <a2fan@hotmail.com> wrote in message
news:_IgJg.13212$1f6.3958@newssvr27.news.prodigy.net...
: Polymorph wrote:
: > Hi,
: >
: > I need help identifying a IIgs RAM card. I recently bought it off eBay
: > and the wording on it doesn't indicate the manufacturer or the name of
: > the card.
:
: Looks like an Apple brand 1MB card to me, or someone cloned it. Are you
: sure it doesn't say Apple silk-screened on the back of it or along the
: rear edge?
:
: There were a couple different versions of the Apple card, with different
: silk screening. This looks like the first generation board to me.

Look more closely Sean. The Logic is different. This uses a 74LS155,
which is a dual 2-4 decoder/demultiplexer, rather than the 74LS139,
which is also a dual 2-4 decoder. All of the Apple Brand 1 MB cards
I have use the 74LS139. It also appears that with only a single jumper,
it may be that this one requires a full 512K bank with it off, and a
full 1 MB with it on.

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