Extremely brief history of PDP computers

I don’t know why I started to put this together. These machines fascinate me, because so much of early computing/hacker type culture happened on them. I started writing a table, but realised a timeline would be more intuitive. In this graph, the price is for a minimal configuration and adjusted for inflation. The time is the memory cycle time, a decent proxy for speed. Some notes: The PDP-1 was created mostly as an experiment. At the time, industrial control systems used either humans or complicated contraptions of logic boards to make decisions. Some engineers at DEC wanted to see if there was a customer base willing to use general-purpose computers instead. The PDP-4 was a variant of PDP-1 that was a little slower and much cheaper. It was not compatible with the PDP-1. The PDP-4 was upgraded with new chip technology and became the PDP-7, which was then optimised further for cost and speed and became the PDP-9. The PDP-5 was created when they realised the PDP-1 and PDP-4 machines…