PDP11 : My other favourite computer system :)

More about PDP11 : My other favourite computer system :)

Well Chat GPT, that certainly doesn't look like the PDP11 that used to be at my college :) It's certainly the right size though :) PDP 11's were awesome little wooees, with a pull-out drawer full of LP-sized PCB's full of TTL chips, and wire-wrapped backplanes. They took about 4 kilowatts to run (I remember hardwiring the whopping great mains cable straight into the fusebox (yes very naughty, but I did switch the power off first) because it took well over 13 Amps). A very nice orthogonal instruction set, and no I/O instructions -- like the 6502 all I/O was memory mapped. And the CPU was microcoded, for efficiency and chip count reduction. Auto-increment and auto-decrement adddressing modes, which allowed any register to be a stack pointer. Load of flashing lights (later LEDs rather than bulbs) to display the contents of the CPU registers. After my college chucked it out, I persuaded the cable company where I worked in the mid 1980's to buy it for £500. We ran a MUD (multi-user adventure game) on it called "Wanderland". When the lease of the office building ran out in 1990, the PDP11 was donated to the Bletchley Park museum. Yay for PDP 11's :)