Re: IIgs Woz Special Edn.: Questions----

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

In article <4JUN199402400468@vax2.concordia.ca>,
Mitchell Spector <spector@vax2.concordia.ca> wrote:
>
> 	One other upgrade I should mention is the VGC chip (Video Graphic
> Controller). Some early GSes have a faulty VGC that causes a pink fringe
> in 80 columns text and monchrome Double-Hi-Res graphics. You'd easily be
> able to tell if you needed the upgrade -- little bits of inversed and 
> flashing pink-pixels appear inbetween text and DHR (mono) graphics. Like
> the ROM upgrade, this too should be available and free of charge. The
> VGC (location H-2) on the motherboard is swapped in this case.

One other point: this is a socketed PLCC chip, which requires a special
tool to remove.  It is definitely a good idea to get an Apple dealer
to do this.

Regarding the "pink fringing": this was most noticeable in the
MouseDesk/Apple II Desktop program included with IIgs System 2.0 and
earlier.  Some IIgses didn't have a noticeable problem on the
80-column text screen, and other machines were only affected with
certain combinations of foreground/background colour.

> The only new features in the ROM 01 are a Monitor command to put the
> 65C816 into 16-bit native-mode and the two programmer CDAs: "Visitor
> Monitor" and "Memory Peeker", which are invoked by the "#" command in
> Monitor.

Actually, they were there in a ROM 0 machine.  You had to know what
address to call to activate them (I think it was FF/1800X, or something
like that).  All that ROM 1 added was the # command to provide an easy
way to install them.

> 	The Apple IIe/IIc/Mac128/512/Plus mice will not function if plugged 
> into the GS's joystick port (unlike the Apple //c), but yes, will function if
> you plug into an Apple //e mouse-interface card.

An important point here:

If you are installing an Apple IIe mouse card into a IIgs, you _must_
have slot 4 set to "your card" to avoid confusing the software (you
can put the IIe mouse card into slot 4, of course).  Also note that a
IIe mouse will not be supported by GS/OS programs on a ROM 3.

The ROM 1 Miscellaneous Toolset mouse routines calls the slot-based
mouse firmware, and searches the slots for a mouse card.  The built-in
mouse firmware accesses the ADB mouse.

The ROM 3 Miscellaneous Toolset accesses the ADB mouse directly, and
the built-in mouse firmware (in slot 4) calls the Miscellaneous Toolset.

This allows a ROM 3 to use the mouse in GS/OS programs even if slot 4
is set to "your card".
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand