Apple IIGS

The Apple IIGS extended the Apple II into a 16-bit computer using the 65C816 processor while maintaining compatibility with most established 8-bit software. Its new graphics modes, Ensoniq wavetable sound, Apple Desktop Bus and mouse-driven GS/OS environment placed the platform closer to the Macintosh.

Early systems shipped with 256KB, while later ROM 3 machines included 1MB and revised firmware. Conservative processor speed protected compatibility but limited the computer against faster 16-bit rivals.

Notable Features

• 65C816 processor provided a 16-bit mode while retaining 6502 compatibility.
• Ensoniq ES5503 supplied 32 digital oscillators and sophisticated sampled sound.
• Super Hi-Res graphics displayed up to 256 colours from a palette of 4,096.

Historical Significance

• The most technically advanced Apple II and bridge between Apple's 8-bit and Macintosh eras.
• Developed a distinctive multimedia and GS/OS software community.

Collector’s Notes

• ROM 01 and ROM 3 machines differ in memory, firmware and motherboard design.
• Battery leakage, RAM expansion condition and original ADB peripherals deserve inspection.

Specifications

Technical Information
Name	Apple IIGS
Manufacturer	Apple
Launched	Monday, September 15, 1986
Launch Price	$999 without monitor
Country	United States
CPU	Western Design Center 65C816 at 2.8 MHz
Units Sold
Operating System	ProDOS 8, GS/OS and Apple II compatibility modes
I/O	RGB, composite, ADB, two serial, game, audio and seven expansion slots
Keyboard	External Apple Desktop Bus keyboard and mouse
Storage	External 5.25-inch and 3.5-inch floppy drives; optional SCSI hard disk
Sound	Ensoniq ES5503 with 32 digital oscillators
Graphics	320 x 200 or 640 x 200; up to 256 colours from 4,096
Display	40/80-column Apple II text and graphical GS/OS desktop
ROM	128KB or 256KB firmware depending on revision
RAM	256KB initially; 1MB on ROM 3 and expandable to 8MB
CPU Speed	2.8 MHz