AT&T UNIX PC

The AT&T UNIX PC is a Unix desktop computer originally developed by Convergent Technologies (later acquired by Unisys), and marketed by AT&T Information Systems in the mid- to late-1980s. The system was codenamed "Safari 4" and is also known as the PC 7300. An updated version with larger hard drive was dubbed the "3B1". Despite the latter name, the system had little in common with AT&T's line of 3B series computers. The system was tailored for use as a productivity tool in office environments and as an electronic communication center.

The initial PC 7300 model offered a modest 512 KB of memory and a small, low performance 10 MB hard drive. This model, although progressive in offering a Unix system for desktop office operation, was underpowered and produced considerable fan and drive bearing noise even when idling. The modern-looking "wedge" design by Mike Nuttall was innovative, and the machine gained notoriety appearing in numerous movies and TV shows as the token "computer".

An enhanced model, "3B/1", was introduced in October 1985 starting at US$8,495 (equivalent to $25,400 in 2025). The cover was redesigned to accommodate a full-height 67 MB hard drive. This cover change added a 'hump' to the case, expanded onboard memory to 1 or 2 MB, as well as added a better power supply.

Convergent Technologies offered an S/50 which was a re-badged PC 7300.

Olivetti released the "Olivetti AT&T 3B1 Computer" in Europe.

The operating system is based on Unix System V Release 2, with extensions from 4.1 and 4.2 BSD, System V Release 3 and Convergent Technologies. The last release was 3.51.

Windowing software (xt/layers) from SVR3 was provided to allow connection to a DMD 5620 graphics terminal.

The UNIX PC has three proprietary S4BUS slots for expansion cards: