https://wiki.retrotechcollection.com/index.php?action=history&feed=atom&title=File%3AApple_IIGS_Hardware_Reference_1989.pdf 2026-09-25T13:38:12Z Revision history for this page on the wiki MediaWiki 1.46.0 https://wiki.retrotechcollection.com/index.php?title=File:Apple_IIGS_Hardware_Reference_1989.pdf&diff=12555&oldid=prev 2026-09-23T04:31:27Z

<p>Upload: primary source for the Apple II/III family verification drive</p> <p><b>New page</b></p><div>== Summary ==<br /> &#039;&#039;&#039;Apple IIGS Hardware Reference&#039;&#039;&#039;, second edition, &quot;for Apple IIGS and 1 MB Apple IIGS&quot; (Apple Computer, Inc., 1989; Addison-Wesley).<br /> <br /> Apple&#039;s own hardware reference for the [[Apple IIGS]]. The source this wiki cites for:<br /> * Processor speed &#039;&#039;&#039;selectable between 1.024 MHz and 2.8 MHz&#039;&#039;&#039;; FPI DRAM refresh &#039;&#039;&#039;reduces the effective speed of programs in RAM by about 8 per cent&#039;&#039;&#039;; programs in ROM run at the full 2.8 MHz.<br /> * Memory: 128K of fast (FPI) RAM plus 128K on the Mega II side, 256K in total, &#039;&#039;&#039;1 MB on the 1 MB logic board&#039;&#039;&#039;; 128K of ROM (256K on the 1 MB board); &#039;&#039;&#039;up to 4 MB of expansion RAM and up to 1 MB of expansion ROM&#039;&#039;&#039;.<br /> * 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.<br /> * Sound: &#039;&#039;&#039;Ensoniq 5503 Digital Oscillator Chip&#039;&#039;&#039;, 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 &#039;&#039;&#039;7-pin molex connector J-25&#039;&#039;&#039; on the main logic board. Separating the oscillators into up to eight channels requires &#039;&#039;&#039;external demultiplexer hardware&#039;&#039;&#039; on that connector - the built-in output is a single mixed channel.<br /> * The 1 MB logic board&#039;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 &#039;&#039;&#039;no longer supports the built-in (Apple IIe style) keyboard - only ADB keyboards&#039;&#039;&#039;.<br /> * The built-in real-time clock with a backup battery, accessible through the Control Panel.<br /> <br /> This is the searchable (OCR text layer) edition scanned by the Internet Archive.<br /> <br /> == Source ==<br /> Internet Archive item &lt;code&gt;Apple_IIgs_Hardware_Reference_HiRes&lt;/code&gt; (text-layer edition).<br /> <br /> == Licensing ==<br /> Copyright Apple Computer, Inc., 1989. Apple has never placed this manual under a free licence. Hosted here for reference and repair use only. &#039;&#039;&#039;Not&#039;&#039;&#039; public domain.<br /> <br /> [[Category:Apple Documentation]]</div>

Josh