SuperMac ColorCard/24 and A/UX 2.0

[Steve Anderson]

(I tried posting this before from a local site, but it doesn't seem to
have made it off campus. Sorry if you see more than one copy.)


Among the discussions I've seen of potential incompatibilities
between A/UX and various hardware products, I haven't seen any
mention of this one, so I thought I'd provide another data point.

I bought a SuperMac ColorCard/24 for my IIci with Apple monitor
because it offered (a) a hardware-implemented virtual screen the
size of a 19" monitor, and (b) the opportunity to add an
accelerator if I found myself using 24-bit color to any great
extent. Unfortunately, I also want to run under A/UX.

The ColorCard/24 implements the virtual screen by catching a signal
on mouse events to make it possible to pan across the frame
buffer. Unfortunately, A/UX doesn't pass this signal on to the
card. If you try to use the virtual screen under A/UX, what happens
is that mouse events just produce alerts to the console window, and
you can't pan. Apple's Technical Answerline suggested that this
could be fixed in software (firmware?) by SuperMac, but with the
strong implication that Apple had no intention of doing anything
about the resulting incompatibility. SuperMac, in turn (both
directly over the phone, and in email from their representative on the
net) has suggested they have no plans to do anything about it
either. My impression was that they see A/UX users as representing
too small a segment of their market to make it worth their while
to re-engineer their product. Of course they may be right, but A/UX
would seem to be an environment where the extra screen real estate
provided by the ColorCard/24's virtual screen would come in especially
handy.

I am also told that the QuickDraw accelerator for 24-bit color is
equally incompatible with A/UX (makes sense, given how touchy A/UX
is about anybody else talking directly to the hardware).

This means that the two potential advantages of this card over some
other 24 bit video cards are absent in the A/UX environment (though
you can of course still use it as an ordinary 640x480 card in
8 bit or unaccelerated 24 bit modes, and in the other ways with the
base MacOS). People interested in A/UX should probably spend their
money on other things.

Steve Anderson
Cognitive Science Center
The Johns Hopkins University

anderson at sapir.cog.jhu.edu