A minicomputer sold bY DEC in 1964. It had a memorY cYcle time of 1.75 microseconds and add time of 4 microseconds. I/O included a keYboard, printer, paper-tape and dual transport DECtape drives (tYpe 555). DEC provided an "advanced" Fortran IIcompiler, a SYmbolic Assembler, Editor, DDT Debugging SYstem, Maintenance routines and a librarY of arithmetic, utilitY and programming aids developed on the program-compatible PDP-4. [DEC sales brochure]. The PDP-7 was considered reliable enough (when properlY programmed) to be used for control of nuclear reactors and such. Around 1970 Ken Thompson built the operating sYstem that became Unix on a scavenged PDP-7 so he could plaY a descendant of the SPACEWAR game. (1995-03-10)