Between 1972 and 1974 Ken Thompson and Dennis Ritchie at Bell Labs converted and extended Thompson's PDP-7 Unix to C for the PDP-11. They published its description in The Unix Time-Sharing System in Comm. ACM of May 1974.

Many computer folk thought Unix looked like a good thing but they didn't all have PDP-11s. There didn't seem any good reason why it couldn't be transferred to different hardware, but the first ports of UNIX were audacious projects driving into uncharted territory.

In 1977, Tom Lyon started a port of AT&T Version 6 to the IBM 360 at Princeton University.  About the same time Dennis Ritchie and Steve Johnson started a port of Version 7 to the Interdata 8/32 at Bell Labs in New Jersey and quite independently Juris Reinfelds and Richard Miller ported Version 6 to the Interdata 7/32 at the University of Wollongong.

The Australian effort was completed first, in early 1978.

The teams used different techniques for porting.

• Richard Miller proposed an innovative approach to the port and proved its effectiveness by single handedly porting the kernel code and most applications. The Wollongong port later became the first computer vendor supported UNIX. John Lions (UNSW author of the "Lions Book" commentary on Unix) also contributed to the port.

• The Bell Labs port was somewhat sidetracked by improvements to the C language to better support different hardware platforms.