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128K ROM Changes

liamur

Active member
This is a thread purely of questions. If these are actually super obvious and I'm just missing something, feel free to disregard my post.

What changed between the 64K ROM and the 128K (Plus/512Ke) ROM? The things I know of, beyond bug fixes, are HFS, the SCSI Manager, the 800K disk driver, and the List Manager. Supposedly Apple integrated some components of the System file, but how much? Could a computer run from just a compatible Finder file on a disk (no System file present)?

Finally, who at Apple did the development on the ROM itself? I thought most of the original Mac team had left by the time work would have started on the 128K ROM.
 

cheesestraws

Well-known member
HD20 support, also.

As far as I know, the dream of running with no System file was long dead by the time the 128K ROMs came around, but I am happy to be corrected.
 

Crutch

Well-known member
Check out Inside Macintosh: Volume IV. That book is basically your official guide to what’s new in the 128k ROM.

There are a bunch of small things (zoom boxes, auto-scrolling menus if they extend past the bottom of the screen, _SeedFill QuickDraw trap) but you covered most of the big ones, except the Time Manager which was also added at that time.
 

Gorgonops

Moderator
Staff member
I also vaguely recall reading they replaced a few routines in the 64k ROM that were “tight but slow” with versions that consumed a little more memory but were faster, but I certainly can’t point to anything specific off the top of my head.
 

liamur

Active member
I was actually referencing Volume IV as I wrote that post. I should have paid more attention, though, because Chapter 3 (the Resource Manager) lists the system resources in the 128K ROM: the four main cursors, drivers .Print, .Sound, .Sony, .MPP, .ATP, the Chicago font, a default MDEF, the Floating-Point Arithmetic package, the Transcendental Functions Package, the Binary-Decimal Conversion Package, the Serial Driver, and a default WDEF. Most of these were stored on disk for the 64K ROM.
HD20 support, also.

That too. Volume IV also discusses performance improvements to QuickDraw and other packages, as well as the creation of font families in the context of the Font Manager.

In hindsight, I should really have just read more carefully. I was most interested in the system resources in ROM, as I was wondering how much benefit they really added.
 
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