PDP-15


The PDP-15 was the fifth and last of the 18-bit minicomputers produced by Digital Equipment Corporation. The PDP-1 was first delivered in December 1959 and the first PDP-15 was delivered in February 1970. More than 400 of these successors to the PDP-9 were ordered within the first eight months.

History

The 18-bit PDP systems preceding the PDP-15 were named PDP-1, PDP-4, PDP-7 & PDP-9.
The last PDP-15 was produced in 1979.

Hardware

The PDP-15 was DEC's only 18-bit machine constructed from TTL integrated circuits rather than discrete transistors, and, like every DEC 18-bit system could be equipped with an optional X-Y display.

Software

The first DEC-supplied mass-storage operating system available for the PDP-15 was DECsys, an interactive single-user system. This software was provided on a DECtape reel, of which copies were made for each user. This copied DECtape was then added to by the user, and thus was storage
for personal programs and data. A second DECtape was used as a scratch tape by the assembler and the Fortran compiler.
Later versions of the PDP-15 could run a real-time multi-user OS called XVM/RSX. The final model, the PDP-15/76 used a small PDP-11 to allow Unibus peripherals to be used.
One other operating system, developed on the PDP-7, was also available for the PDP-15:
and digitizing tablet