classiccmp-digest V1 #163

From: John Wilson <wilson_at_dbit.dbit.com>
Date: Wed May 10 00:20:39 2000

On Tue, May 09, 2000 at 06:39:18PM -0000, Eric Smith wrote:
> The Macintosh OS has gone through multiple cycles of adding large
> chunks of new functionality to the System file, then moving those
> pieces into ROM. Unfortunately when the code gets moved into ROM,
> it doesn't usually get removed from the System file, because it still
> is needed for older Macs since Apple typically does not offer ROM
> upgrades.

I may have this wrong, but I remember being told that this meant having a
pretty complicated boot process where the ROM versions of various routines
could be replaced by a newer version off the disk, and that the amount of
code that had to be loaded from disk was sort of proportional to the age of
the computer. And supposedly this meant that a generic (works on any machine)
boot disk didn't have much free space, but if you (somehow) pared it down
to have only the patches required for your particular computer (instead of
all possible Macs throughout history) you could have a lot more space on
the disk. Sound right?

Wasn't there some point where they dropped support for the early Macs with
less ROM (64 K vs. 128 K or something??????), or am I making that up? If so,
was it just because thin Macs didn't have space for the bloat, or was there
really something wrong with what was in ROM that was beyond help?

John Wilson
D Bit
Received on Wed May 10 2000 - 00:20:39 BST