PDP-1

PDP-1

The PDP-1 — Programmed Data Processor-1 — was DEC's first computer and the machine that taught computing to play. Ben Gurley designed it in 1959 straight from MIT's TX-0/TX-2 lineage (themselves descendants of Whirlwind), priced it at a then-astonishingly-low $120,000, and made it the first commercial machine with a graphics display — the Type 30 CRT — at a time when most computers' output was a typewriter or a deck of cards. Fifty-three were built.^[1]

The hardware was honest minimalism: 18-bit word, 187 kHz, 4K words of core — a machine you could sit in front of, hear running, and watch. That last part is what changed culture: the first unit went to BBN in 1960, and the MIT installation became the gymnasium of the first hacker generation — the TMRC crowd who named themselves for the word "hacker." On this machine they wrote Spacewar! (Steve Russell, 1962) — one of the first real video games, spread by hand to every PDP-1 site — plus the first text editor, the first word processor, and the first interactive debugger, one of the very earliest time-sharing systems (the BBN Time-Sharing System), some of the earliest computer music, and MUMPS's own ancestors (BBN's TELCOMP line). The ARPANET IMP software was composed, edited, and assembled on BBN's PDP-1d — the machine the internet's first packet switches were written on.^[2]

The machine games began on

Spacewar! deserves its own paragraph: two toroidal-wraparound rocketships, a starfield, a gravity well, hyperspace — written in PDP-1 assembly by Russell with the TMRC crew, running on the Type 30's vector display. It is possibly the first program written purely to be fun — and it propagated the way software now does: copied to every PDP-1 installation, patched and improved at each one (gravity, hyperspace, scoring), making it also one of the first open-source-style collaborative programs. The game is a canonical ancestor of the entire industry that followed.^[3]

Where it sits

The PDP-1 is the hinge between the mainframe priesthood and the minicomputer congregation — Whirlwind's real-time DNA commercialized, the first display-native computer, and the birthplace of games, hacking, and everything interactive computing became. DEC built an empire on the series it founded.

Check your understanding

• Who designed the PDP-1, and from what lineage?
• What made it culturally different from every computer before it?
• What was Spacewar! — who wrote it and when?
• How much did it cost, and why did that matter?