Date: Wed, 27 Oct 1993 19:49:25 +0100
From: Dominique Petitpierre <petitp@divsun.unige.ch>
2415*/S=petitp/OU=divsun/O=unige/PRMD=switch/ADMD=arcom/C=ch/@MH S>
To: Info Mac <info-mac@sumex-aim.stanford.edu>
Subject: son of SUMMARY: Is the Apple 8*24 GC video display board worth
something?
Resent-To: backmod
Resent-Date: Wed, 27 Oct 1993 18:56:02 PDT
Resent-From: Info-Mac Moderator <macmod@camis.Stanford.EDU>
The summary that I posted posted in Info-Mac and comp.sys.mac.hardware a few
days ago ("SUMMARY: Is the Apple 8*24 GC video display board worth
something?") stirred a few more comments that relativize the very negative
opinions that were expressed.
In short:
The card can be used as a good non accelerated 24 bits color card if it is
used with the proper drivers (8*24GC 7.0.1 driver and "Cache On" extensions).
The possibility of extending its GWorld memory (with the same SIMMS as for a
MacIIfx) makes it useful for some applications. Newer versions work with a
832x764 pixels 16" monitor.
As the price that I was quoted (400$ second hand) is still more than the
standard 24 bits card (330$ list price in Switzerland), I won't buy it.
Here are the comments I received. Many thanks to their authors who took the
time to write to me! For those who missed it, the first summary is available
by FTP on sumex-aim.stanford.edu in the file
/info-mac/info/hdwr/worth-of-8-24-gc-card.txt
[Note to the Info-Mac moderator: could you please append this second summary
to that file? Thanks!]
================================================================
From: (Bailey Szeto) <bszeto@netcom.com>
Here's some additional info/clearification on the 8.24GC board. I recently
was employed by Apple to do some compatibility testing and got the chance
to play with the 8.24GC a bit.
In article <1993Oct20.090854.27980@news.unige.ch> you wrote:
: - Name: Macintosh II Display Card 8.24 GC (I believe this is what appears in
: the window when you click the "Options" button of the "Monitors"
: Control Panel.)
: - resolutions:
: max 16.7 million colors on a 640 x 480 pixels monitor
: max 256 grays on a 640x870 pixels monitor
: max 256 grays on a 1152x870 pixels monitor
Newer versions of the card will also support 16.7 million colors on a
832x764 monitor (16" display). This was the last change to the card, in
fact the code name for this project was "Cheap Date".
: - video: RS-343 and RS-170 (NTSC, interlaced); only 256 colors with "Apple
: convolution" for flicker free display.
: - extensibility:
: 2 SIMMS slots to add up to 8 MB extra memory for "processing
: large off screen graphics" (retranslated back from French :-),
: notice that it won't let you use a larger monitor).
The extra Simm slots are for a expanded "GWorld". It is indeed for processing
large off screen graphics, but not many programs take advantage of this.
: Facts from Larry Pina's book "MacIntosh Repair and Upgrade Secrets", Simon &
: Schuster (pp 132, 140, 142,144, 149, 169):
: - DRAM upgrade (p 140):
: Official Apple Macintosh Display Card DRAM Kit (part M0505LLA/A, 2
: 1MB SIMMS) or generic SIMMS up to 8MB total.
The second part of the above statement in incorrect. It uses 64 pin simms
(the same as the IIfx, laserwriter NTX simms).
: Answers received by Wednesday October 20th:
: >The acceleration on the GC is incompatible with System 7. You have to turn
: >it off.
This used to be true, but it has been fixed. There is a GC extension for
system 7.01 (not 7.1). However, turning accelleration on doesn't really
speed things up. You might get a 10% increase in graphics performance,
but you'll also get a speed hit on other areas. In fact, the speedometer
results show that a IIci is *slower* with acceleration turned on.
The 8.24GC card is not what you're looking for if you want an accelerated
card. However, if it is a newer version (one that supports 24 bit color
on 16" monitors) than it might be worth a look if the price is cheap
enough. The 8.24GC is a fine *unaccelerated* display card, it's when
you use the acceleration INIT that problems appear.
By the way, last I heard some engineer had written a JPEG program that
uses the GC's RISC processor to display JPEGs really quickly. He told me
"I couldn't stand to let that huge chunk of silicon just sit there, so
I might was well take advantage of it somehow..."
.......
================================================================
From: Sam Sheng <ssheng@zabriskie.EECS.Berkeley.edu>
......
In any case, I've been quite happy with my 8*24GC running with a IIfx.
I've had few compatibility problems, and the 8*24GC 7.0.1 driver
does exist (still works fine, even under System 7 Pro). Mainly, the
problems I've had have been with games that do ill-behaved direct
screen writes, but for example Chuck Yeager's Air Combat works just
fine, both in direct screen-write and Quickdraw modes.
There is one little bug that Apple hasn't told a lot of people how
to solve; the driver turns off both the data and program caches. There
was a little init called Cache On that fixed this problem, and your
machine really flies after this. (Several people have complained
that the machine actually got slower after putting the System7
8*24GC driver, most notably IIci owners. This is the cause).
The GWorld memory is used by the on-board AMD29000 processor to
do local drawing work during idle cycles. It is NOT VRAM (as a lot
of people seem to think). This accelerates drawing
speeds by quite a bit, since you're not limited by the NuBus backplane.
There were initial plans to have the quicktime init download decompression
code to run in GWorld, but I think it got shelved. The one notable program
that supports GWorld heavily is Photoshop 2.5.1; it makes a big difference
in speed when working with and without GWorld (make sure it's 2.5.1;
2.5 didn't work right for some reason).
All in all, it was worth it to me; I paid something like $800 for it
back about 2 years ago, and I haven't regretted it. You do have to
have the Cache On init to make it work right, but beyond that it's
served me well. BTW, at this point, I have two of them in the fx
just for kicks (the second one was free; somebody was throwing it
out).
I seem to be the minority opinion on this, though,
from your other responses.... =)
........
================================================================
From: Arthur B. Busbey <BUSBEY@TCUCVMS.bitnet>
.......
I just ran across the e-mail concerning the 8-24GC card from Apple. I also
think you made the best decisions - there are other accelerated 24-bit
cards out there that work on 040 machines and in System 7.0.x and 7.1. I
just dropped this line to explain about the RAM slots on the card (they are
also on other accelerated cards).
This RAM, as someone in the messages said, is for GWorld support. GWorld
is a set of screen management routines in System 7.x that greatly facilitate
programming in color for multiple monitors and for allowing easier animation
on single monitors. They allow the programmer to write screens into offscreen
buffers as thought they were writing to an active screen and then move the
GWorld (GraphicsWorld) buffer into the real screen very fast. Those programs
that support (e.g. use) GWorld calls greatly benefit from additional GWorld
RAM out on graphics cards, because new screens (or portions of current
screens) can be saved in the GWorld RAM and very rapidly (on the card)
be moved into the 'real' screen. I have 4 megabytes of RAM in the GWorld
buffer on my RasterOps 24si card and can really tell the difference in
Photoshop and in the satellite image processing software Multispec (which both
use GWorld calls).
.........
--
Mr. Dominique Petitpierre / ISSCO, University of Geneva, Switzerland
petitp@divsun.unige.ch/ S=petitp;OU=divsun;O=unige;PRMD=switch;ADMD=arcom;C=ch