Released alongside the Macintosh LC and the Macintosh Classic, the Macintosh IIsi was another odd-ball Macintosh. In a tool-less case resembling a puffed-up Macintosh LC, the Macintosh IIsi was somewhat of a redesigned Macintosh IIci with a 68030 processor but no NuBus slots or FPU. It has a single PDS slot in a type it shares with the Macintosh SE/30).

The Macintosh IIsi features a 20 MHz Motorola 68030 processor, 2 MB or 5 MB RAM, a 40 MB, 80 MB or 160 MB SCSI hard disk drive and a 1.44 MB floppy disk drive. Expandability was through a single PDS slot and serial, ADB, SCSI, and audio in/out ports.

I received this Macintosh IIsi in a trade with an online friend and it features 5 MB RAM, a 120 MB hard disk drive. It is featured with a Macintosh Color Display, Apple Extended Keyboard II and Apple microphone, booting into System 6.0.8.