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

== Summary ==
'''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.

== Source ==
Mirror of ftp.apple.asimov.net at <code>mirrors.apple2.org.za</code>, documentation/hardware/machines.

== Licensing ==
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.

[[Category:Apple Documentation]]