File:Apple IIGS Hardware Reference 1989.pdf

Apple IIGS Hardware Reference, second edition, "for Apple IIGS and 1 MB Apple IIGS" (Apple Computer, Inc., 1989; Addison-Wesley).

Apple's own hardware reference for the Apple IIGS. The source this wiki cites for:

• Processor speed selectable between 1.024 MHz and 2.8 MHz; FPI DRAM refresh reduces the effective speed of programs in RAM by about 8 per cent; programs in ROM run at the full 2.8 MHz.
• Memory: 128K of fast (FPI) RAM plus 128K on the Mega II side, 256K in total, 1 MB on the 1 MB logic board; 128K of ROM (256K on the 1 MB board); up to 4 MB of expansion RAM and up to 1 MB of expansion ROM.
• Super Hi-Res: 320 or 640 pixels across, 200 lines, 16 colours per line chosen from 4096; a 320-mode pixel can be any of 16 palette colours, a 640-mode pixel one of only 4, with the 16 palette colours split into four groups of four.
• Sound: Ensoniq 5503 Digital Oscillator Chip, 32 independent oscillators, 64K of dedicated sound RAM, interfaced through the Sound GLU. Sound leaves the machine through the built-in speaker, the external speaker jack, or the 7-pin molex connector J-25 on the main logic board. Separating the oscillators into up to eight channels requires external demultiplexer hardware on that connector - the built-in output is a single mixed channel.
• The 1 MB logic board's differences: the new ADB microcontroller with sticky keys and keyboard mouse, text page 2 shadowing, the cold-boot bit in the Speed register, and the fact that it no longer supports the built-in (Apple IIe style) keyboard - only ADB keyboards.
• The built-in real-time clock with a backup battery, accessible through the Control Panel.

This is the searchable (OCR text layer) edition scanned by the Internet Archive.

Internet Archive item Apple_IIgs_Hardware_Reference_HiRes (text-layer edition).

Copyright Apple Computer, Inc., 1989. Apple has never placed this manual under a free licence. Hosted here for reference and repair use only. Not public domain.