All over the place, the VAX 9000 is being described as DEC’s first stab at making a mainframe, which seems to prompt (no, not beg!) the question, what was the PDP-10? What was the PDP-10? It was a 36-bit mainframe that ran the TOPS-10 timesharing operating system, and also an operating system called Tenex, was particularly popular in universities, and was eventually renamed the DECsystem-10 because people assumed that anything called PDP anything had to be a mini; the DEC-10, and its smaller derivative, the DECsystem-20, remained active members of DEC’s product line for between 10 and 15 years, and it was only about 1982 that DEC decided to phase the line out and replace it with future mainframe-power VAXes.
