3 ms·

User Manual for the Harvard Mark 1 Electro-Mechanical Computer (1946)

32 points by eigenvalue 4y ago

eigenvalue 4y ago
This is a really fascinating document. It was written by the lead designer (Howard Aiken) and Grace Hopper, who is well known in CS circles. What I like most about the machine is that it feels easier to understand how it operates in an intuitive way, particularly because it is all in decimal as opposed to binary. And the machine was accurate to a very high number of decimal places, and could also directly produce high-quality printed tables of mathematical tables (the first big job it worked on was to prepare large tables of Bessel functions).
dyerjohn 4y ago
What we really want is audio of a relay computer working. It must have been quite the sound!!
- aplc0r 4y ago
  Here is one from 1958 in Japan that has been preserved. The whole video is worth watching, but here is a demo of a running calculation: https://youtu.be/_j544ELauus?t=1027 https://youtu.be/_j544ELauus?t=1027.
  - eigenvalue 4y ago
    One of my favorite YouTube channels. Marc has tons of amazing vintage computer content. The Apollo guidance computer series in particular is great.
  - fathyb 4y ago
    That was a great watch, thanks for sharing!
- bklaasen 4y ago
  Yes, it made a racket! There is a description of the Harvard Mark I crashing in Beyer's "Grace Hopper and the Invention of the Information Age": > Hopper, Campbell, and Bloch invested substantial energy in developing practices and procedures for debugging. Like physicians, they identified symptoms, made diagnoses, and prescribed treatments. Sometimes symptoms were obvious, as when Mark I would come to a crashing halt: “The crash of that thing sounded as if a plane had run into the building,” Hopper recalled. ”You never heard such a crash in your life.”
  - anyfoo 4y ago
    Is that where the term of a computer "crashing" comes from? Similar to how the term debugging may or may not have been "reinforced" by the finding of an actual moth on the Mark II (it wasn't its origin, according to Wikipedia: https://en.wikipedia.org/wiki/Debugging#Etymology https://en.wikipedia.org/wiki/Debugging#Etymology ).
    - abudabi123 4y ago
      Perhaps debugging comes from a mathematical joke in base 6 encoding.

32 points by eigenvalue 4y ago

This is a really fascinating document. It was written by the lead designer (Howard Aiken) and Grace Hopper, who is well known in CS circles. What I like most about the machine is that it feels easier to understand how it operates in an intuitive way, particularly because it is all in decimal as opposed to binary. And the machine was accurate to a very high number of decimal places, and could also directly produce high-quality printed tables of mathematical tables (the first big job it worked on was to prepare large tables of Bessel functions).

dyerjohn 4y ago

What we really want is audio of a relay computer working. It must have been quite the sound!!

aplc0r 4y ago
Here is one from 1958 in Japan that has been preserved. The whole video is worth watching, but here is a demo of a running calculation: https://youtu.be/_j544ELauus?t=1027 https://youtu.be/_j544ELauus?t=1027.
- eigenvalue 4y ago
  One of my favorite YouTube channels. Marc has tons of amazing vintage computer content. The Apollo guidance computer series in particular is great.
- fathyb 4y ago
  That was a great watch, thanks for sharing!
bklaasen 4y ago
Yes, it made a racket! There is a description of the Harvard Mark I crashing in Beyer's "Grace Hopper and the Invention of the Information Age": > Hopper, Campbell, and Bloch invested substantial energy in developing practices and procedures for debugging. Like physicians, they identified symptoms, made diagnoses, and prescribed treatments. Sometimes symptoms were obvious, as when Mark I would come to a crashing halt: “The crash of that thing sounded as if a plane had run into the building,” Hopper recalled. ”You never heard such a crash in your life.”
- anyfoo 4y ago
  Is that where the term of a computer "crashing" comes from? Similar to how the term debugging may or may not have been "reinforced" by the finding of an actual moth on the Mark II (it wasn't its origin, according to Wikipedia: https://en.wikipedia.org/wiki/Debugging#Etymology https://en.wikipedia.org/wiki/Debugging#Etymology ).
  - abudabi123 4y ago
    Perhaps debugging comes from a mathematical joke in base 6 encoding.