UNIX is an operating system developed at Bell Labs in 1969 by Ken Thompson and Dennis Ritchie. It is still widely used today and has inspired many clones. In the late 1970s Western Electric developed the 32-bit BELLMAC-32 (later known as the WE 32000) processor for use in high availability applications within the telephone network. These 3B systems ran Duplex Multi Environment Real Time (DMERT) which used the modular kernel in the System V release 2 version of UNIX. The 3B was not a mainframe, but used micro-components to build out a mini-computer footprint. The 3B platform is still in use with the 5ESS switch.

In 1983 AT&T offered the much smaller 3B2 model 300 desktop for business use. The Museum has several AT&T Unix desktop systems in our collection.