Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!jarthur!nntp-server.caltech.edu!toddpw
From: toddpw@nntp-server.caltech.edu (Todd P. Whitesel)
Newsgroups: comp.sys.apple2
Subject: Re: IIgs ROM revisions
Message-ID: <1991Apr4.100923.18800@nntp-server.caltech.edu>
Date: 4 Apr 91 10:09:23 GMT
References: <1991Apr4.073355.24299@mnemosyne.cs.du.edu>
Organization: California Institute of Technology, Pasadena
Lines: 46

kreme@isis.cs.du.edu (Max Headshop) writes:

> Most of the nifty new things on the Mac were taken from
>the Apple II developmetn teams inivations.

Initially, maybe, but with an order of magnitude more people working on it
the Mac system software has far outgrown the GS's. The GS's may be better
designed in many ways, but Apple has not implemented some crucial things
yet -- things that would make a MultiFinder actually feasible, for example.

> Then Apple limited the GS to 4 Megs of DMA (rumor is it was
>because they didn't want the GS having more RAM than their Macs).

That's totally unfounded. It is a design limitation of the DRAM control
section of the FPI chip, which was designed to handle addressing and refresh
for four ROWS, NOT MEGS, of DRAM's. The FPI also only supports 64K and 1 Meg
rows (Be glad -- Jobs still worked there and he thought the original Mac ONLY
needed 128K) so the limit on RAM fully controlled by the FPI (and therefore
totally DMA compatible) is 4 megs. AE's original hack to get more than four
rows of chips on the GS-Ram cards broke when DMA accesses occured, because of
a timing limitation in the early 65816's that the FPI had to respect. So they
had to design around things again. But it is possible to DMA over 4 megs in
a GS, you just need to have a memory card that's smart enough.

If all that went over your head, the 4 meg DMA problem DID NOT have anything
to do with rivalry and the Mac. It was an unfortunate engineering fiasco.

>The GS (stock) already outperforms the Mac.

The stock GS might outperform a Lisa, but that's about it. Even the 128K Mac
runs faster than the stock GS. A Zipped GS, however, is different.

> It has a CLI *AND* a GUI.

Damn straight. There's something fundamentally right about .CONSOLE, if only
Mike Westerfield would stop using the damn texttools for I/O redirection...

[more debatable claims]

I won't comment on these. You got into stuff that's value judgement and
personal preferences, and it appears that a good number of Mac owners don't
agree with you. I agree the GS is better, but that's because I like all
the things the Mac doesn't have (CLI, synth, etc).

Todd Whitesel
toddpw @ tybalt.caltech.edu