A significant piece of computing history has surfaced from a 50-year-old magnetic tape. The source code for the Fourth Edition of Unix, long thought to be lost, has possibly been recovered from a DECtape originating from Bell Labs in 1973. Prior to this discovery, only the manuals for Unix v4 were known to have survived.
The finding was brought to public attention by Australian computer scientist Warren Toomey and The Unix Heritage Society. The process began when a collector of vintage computer hardware sent images of the forgotten tape to Toomey for analysis.
Discovery and Initial Analysis
The artifact in question is a DECtape, a type of magnetic storage medium used with PDP-11 computers, which were instrumental in the early development of the Unix operating system. Examination of the tape’s contents revealed a file system structure that is characteristic of an early Unix distribution. The data was successfully extracted from the tape images, allowing for a detailed review of its contents.
Contents of the 1973 Tape
The recovered file system includes directories with names that strongly indicate the presence of Unix source code. Key directories found on the tape include /usr/source/s1, /usr/source/s2, and /usr/sys/ken. The directory named “ken” is a direct reference to Ken Thompson, one of the principal creators of Unix at Bell Labs. These directories and their contained files are consistent with the structure of the Fourth Edition Unix source tree. The Unix Heritage Society is currently working to restore the recovered code to a bootable state.
Concise Cyber 