File:Apple IIGS Technical Note 26 ROM Revision Summary 1989.pdf

Apple IIGS Technical Note #26: ROM Revision Summary (Apple Computer, Inc., Developer Technical Support; written by Rilla Reynolds, October 1987; revised by Matt Deatherage, September 1989).

Apple's own summary of what changed between the Apple IIGS ROM versions. It is the authority for:

• Apple's naming: ROM 0, ROM 1 and ROM 3. ROM 2 was skipped "since there was already enough confusion about the first version, ROM 0, and the second version, ROM 1".
• ROM 3 is 256K, double the size of ROM 1, and began shipping in August 1989.
• ROM 1 requires System Software 2.0 or later; ROM 3 requires System Software 5.0 or later. System Software no longer supports ROM 0.
• Dealers could upgrade machines with serial numbers lower than E704... to ROM 1 on request.
• ROM 3 hardware changes referred to in the firmware: the new keyboard microcontroller that allows finer mouse tracking and the keyboard-mouse feature, and the new CYA chip that handles text page 2 shadowing and the power-up bits.
• The Window, Menu, Control, Line Edit, Dialog, Scrap, Font and List Managers moved into ROM on ROM 3.

Mirror of ftp.apple.asimov.net at mirrors.apple2.org.za, documentation/hardware/machines.

Copyright Apple Computer, Inc., 1987-1989. Apple developer documentation, never placed under a free licence. Hosted here for reference and repair use only. Not public domain.