Rebuilding the IBM 1401 | Hacker News Reader

Rebuilding the IBM 1401

spectrum.ieee.org

21 pointspieceofpeace5 comments

The first computer I used. You could see each bit of memory with the naked eye: little metal donuts strung on wire grids.

http://members.optushome.com.au/intaretro/1401Core-9L.jpg

Though the CPU was feeble by present standards, peripheral devices like the card reader and printer were already quite evolved, and were very impressive for mechanical devices. The printer could print letters so fast that the pitch was a high whine.

Computers were not seen then quite the way they are now. It was almost as if the CPU was something that combed the data on its way from card reader to printer. That's why they called what they now call IT "data processing" then.

(IIRC it's had 3 names so far: DP, then MIS, then IT.)

Somewhere in his work, my father picked up a keychain fob that had some core memory elements as well as a microprocessor embedded in Lexan. I remember as a kid looking at it through the family microscope (having no idea at the time how unusual either the fob or the family microscope were).

I cut my teeth on the PDP's and then Vaxen at his employer that they kindly let me visit on site and dial into from the home terminal. As the article says, you never forget your first love.

My first was an IBM 7094, but over in a corner was a trusty 1401 which was used to copy card decks of programs onto tape for the 7094 to execute. The output tapes were carried back to the 1401 for printing.

The 1401 was a marvel of simplicity. Pressing the start button would read one card from the card reader and start executing the code on the card. The boot card would read the rest of the boot program from the card reader and you were ready to go.

1401 machine language was my first assembly language experience - I wrote a one card card deck duplicator and a one card card deck printer. Those photographs bring back memories - I can hear the printer playing The Star-Spangled Banner.

The computer history museum is wonderful. For all that our field of endeavor is (relatively) young, the museum makes it clear that we already have a rich, varied and illuminating history.

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