Subject: Re: Color video *refuses* to work...
To: Dinsdale Piranha <dinsdale@vegas.infi.net>
From: Kevin Coffee <kpc@enteract.com>
List: port-mac68k
Date: 12/01/1996 12:05:58
Are you sure it's not a "Apple Macintosh Display Card 8-24 GC"? If so, it
should no longer be considered 'plain vanilla' - perhaps more like 'rocky
road'.

In addition to driving a monitor, the 8-24 GC is a QuickDraw accelerator,
with it's own ROM-based instruction set. As the man used to say "I've owned
twelve of these".  I can't locate any docs for the thing, but a brief
sojourn down memory lane stumbled over the following Apple Tech Note:

"When a drawing call is issued, GC IPC (Interprocess Communication) takes
control of the call and passes it to GC QuickDraw.  After the normal port
set up (which involves caching the port parameters if this is the first
drawing call after the port was set), GC QuickDraw returns control to the
application through the IPC and performs, in parallel, the drawing to its
own monitor as well as any other monitors that may be affected by  the
operation.  The application then continues its execution, probably issuing
more drawing calls that get executed in the same asynchronous manner.

The result of this mode of operation is improved performance, since the
application gets control back immediately after issuing the call and the GC
QuickDraw moves video data to its own video buffer as well as that of other
cards in a more rapid manner by using block transfers and without requiring
any action by the main processor."

<Deaccelerated _CopyBits & 8=8024 GC QuickDraw>
<Imaging M.IM.GCQDCopybits>
<Written by:     Guillermo A. Ortiz      February 1991>

Additional observation:

These things are almost completely incompatible with current Mac OS and
after an initial attempt to make them work with 7.0, I haven't heard peep
from Apple about software support (of course, I haven't been looking that
hard either.)

They _will_ drive a 13" RGB at 24-bit (golly), but the accelerator routines
are now very much 'in the way' of the MacOS.

If it's not that card, well...   never mind.

-Kevin

At 12:52 AM 12/1/96, Dinsdale Piranha wrote:
>Alright, I've gotten grftest1.c and grftest.c from Taras' site.  Compiled
>and attempted to run them, grftest1 first (per readme's instructions) while
>running under his "GENERIC 961024" kernel (which boots just fine, I might
>add).  Does the *exact* same thing as when I try to run the latest color X
>server; that is, all video signal dies and the machine freezes.  I've run
>his MacOS "video_data" execs but don't understand any of the stuff in the
>ROM dump output file.
>
>I find it hard to believe (however, it's the only explanation for this
>problem that I can come up with) that such a plain-vanilla Apple product as
>my video card is incompatible; surely there must be at least one other
>MacBSD user out there with the same one (to note, it's an "Apple Macintosh
>Display Card 8 * 24" and I don't remember the exact year, but it's pretty
>old; I was still running system 6.0.3 when I got it, if memory serves).
>Machine is a IIcx, by the way; monitor is the standard 13" 640x480 Apple
>RGB that came with it.
>
>Can anyone offer any insight, theories, anything?  :)

K e v i n  C o f f e e   /   d i f f w e r k s
<diffwerk@enteract.com> <kpc@enteract.com>