Ken Shirriff on Nostr: The computer had no RAM but stored everything (code, data, registers) on a hard disk ...

The computer had no RAM but stored everything (code, data, registers) on a hard disk that held just 2727 words. The disk had multiple fixed heads (see photo), so it didn't need to seek. The disk provided one bit at a time to the serial computer, which would perform the instruction and write the results back to disk one bit at a time. 8/N