The PDP-9, the fourth of the five 18-bit minicomputers produced by Digital Equipment Corporation, was introduced in 1966.[1]: P.10 A total of 445 PDP-9 systems were produced,[2] of which 40 were the compact, low-cost PDP-9/L units.[3]
History
The 18-bit PDP systems preceding the PDP-9 are the PDP-1, PDP-4 and PDP-7. Its successor is the PDP-15.
Hardware
The PDP-9, which is "two metres wide and about 75cm deep,"[4] is approximately twice the speed of the PDP-7. It was built using discrete transistors, and has an optional integrated vector graphics terminal. The PDP-9 has a memory cycle time of 1 microsecond, and weighs about 750 pounds (340 kg).[5]: 1-7–1-8 The PDP-9/L has a memory cycle time of 1.5 microseconds, and weighs about 900 pounds (410 kg).[6]: 1-1, 15-8
It is DEC's first microprogrammed machine.[7][5]: 3-16
The system came with an OS that functions as single-user keyboard monitor, called ADSS (ADvanced Software System).[12] DECsys provided an interactive, single-user, program development environment for Fortran and assembly language programs.[13]
Both FORTRAN II[2] and FORTRAN IV[14] were implemented for the PDP-9.
The PDP-7, of which 120 were sold,[1]: p.8 was described as "highly successful".[2] The PDP-9 sold 445 units. Both have submodels, the PDP-7A[NB 1] and the PDP-9/L,[NB 2] neither of which accounted for a substantial percentage of sales.[1][NB 3]