Re: Upgrading IIgs Woz Model

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

In article <4tvqvh$do8@crcnis3.unl.edu>, schaffin@unlinfo.unl.edu (Scott
Chaffin) wrote:

>I recently acquired an Apple IIgs Woz Limited Edition and was
>wondering what my upgrade options are.

The first question is whether it has already been upgraded to ROM 1.  Does
it indicate a version number and copyright message at the bottom of the
title screen, or does it just say "Apple IIgs" at the top?

If it just says "Apple IIgs", then you have a ROM 0 machine which will
have to be upgraded to ROM 01 if you want to run any recent IIgs software
(it will work fine as a fancy IIe clone).

You might also need to upgrade the Video Graphics Controller chip, if it
is an old enough machine.  The original version of the VGC has a cosmetic
problem which causes pink fringing effects on the screen in monochrome
double hi-res graphics mode on an RGB monitor.  It also affects 80-column
text mode on some machines (possibly only with some combinations of
foreground and background colour).

The VGC is the socketed PLCC chip under the power supply.  The faulty one
is labelled 344S0046-A or S44S0046-0 (I'm not sure which).  The
replacement one in my machine is 344S0046-C, but I've also heard of other
versions that have the problem fixed.

>I know that Apple used to offer an upgrade to the ROM 01 version of the
>machine, but I'm not sure what was involved in that upgrade.

The ROM upgrade is a simple swap of the ROM chip.  The VGC upgrade (which
may not be necessary) is similar, but you need a PLCC extractor tool to
get the existing chip out.

The motherboard is identical.

It is unclear whether Apple still offers this upgrade (they may do in some
countries).  It was free.

Alltech Electronics may be able to supply the chips, but you will have to
pay for the replacement parts.

-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand