Apple Macintosh IIsi

Apple Macintosh IIsi was introduced in 15 October 1990 as a lower-cost compact 68030 desktop positioned between the LC and professional Macintosh II models. It used a Motorola 68030 at 20 MHz with 2MB standard; expandable to 65MB. Compact case introduced a less expensive modular Macintosh format.

Integrated video and optional NuBus adapter offered useful flexibility, though shared memory and the 20MHz bus limited speed.

Notable Features

• Compact case introduced a less expensive modular Macintosh format.
• PDS adapter could provide a NuBus slot and optional floating-point unit.
• Integrated video borrowed main memory for its frame buffer.

Historical Significance

• Integrated video and optional NuBus adapter offered useful flexibility, though shared memory and the 20MHz bus limited speed.
• Its place in the range reflects Apple's progression from the original compact Macintosh toward broader professional, educational and portable markets.

Collector’s Notes

• Leaking capacitors and the soldered PRAM battery area deserve immediate inspection
• Original keyboards, mice, storage devices and model-specific accessories help document a complete period configuration.

Specifications

Technical Information
Name	Apple Macintosh IIsi
Manufacturer	Apple
Launched	Monday, October 15, 1990
Country	United States
CPU	Motorola 68030 at 20 MHz
Units Sold
Operating System	System 6.0.7 through Mac OS 7.6.1
I/O	Built-in video, SCSI, two serial, ADB, audio and one processor-direct slot
Keyboard	External ADB keyboard and mouse
Storage	1.44MB floppy and internal SCSI hard disk
Sound	Eight-bit mono sound
Graphics	Integrated colour graphics using system RAM
Display	Built-in colour video
ROM	512KB ROM
RAM	2MB standard; expandable to 65MB
CPU Speed	20 MHz