4 ms·

FGJKQW makes sense because almost all the rest of the alphabet was used for the instruction set (one letter per instruction) so these were left over. For the l

FGJKQW makes sense because almost all the rest of the alphabet was used for the instruction set (one letter per instruction) so these were left over. For the life of me, I can't figure out why ORDVAC use KSNJFL. If you Google around you'll find the claim that this was because in figure shift mode the input teletype produced 01010 to 01111 in binary on the tape for those letters. Except, I can't find a 5 level code that actually conforms to that. It's certainly not Baudot as some claim. And if you look at the manual the claim about figure shift isn't even true for the actual code used. https://www.ideals.illinois.edu/items/55048 https://www.ideals.illinois.edu/items/55048

deleted 4y ago
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kps 4y ago
> https://www.ideals.illinois.edu/items/55048 https://www.ideals.illinois.edu/items/55048 On p4 the code has KSNJFL punch binary 10–15. It starts with a permutation of Baudot ITA2 (notice the QWERTYUIOP/1234567890) to make 0–9 punch their values.
- jgrahamc 4y ago
  Yes. But why that permutation? And although there is a relationship (like Q and 1 being on the same key) there isn't a relationship with Baudot or ITA2 (e.g. Q/1 isn't 00001 it's 11101).
  - kps 4y ago
    In case you're not already aware (and/or for readers who aren't, because I wasn't yesterday), they made substantial modifications to Model 15 Teletypes to get their chosen coding and key layout (numeric-pad-like rather than QWERTY), including modifying and permuting levers, type bars, and keycaps. It could be that KSNJFL was somehow most convenient in that respect, though it's hard to imagine. https://archive.org/details/modificationofte56mill https://archive.org/details/modificationofte56mill
    - jgrahamc 4y ago
      Yeah. It's pretty interesting because they clearly did this super intentionally. As you say they moved everything around. Since they are using the existing keycaps which have Q/1, W/2 etc. they lose QWERTYUIOP but they've still got ASDFGHJKLZXCVBNM from which to get the hex digits. The one clue I haven't explored deeply is that there are references to ORDVAC and ILLIAC I using the same teletype equipment as prepared for the Institute of Advanced Study (IAS) Machine (i.e. von Neumann's machine). These machines all have the same principles and it's possible that these teletypes (prepared by the US Bureau of Standards) are the source of KSNJFL.

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kps 4y ago

> https://www.ideals.illinois.edu/items/55048 https://www.ideals.illinois.edu/items/55048 On p4 the code has KSNJFL punch binary 10–15. It starts with a permutation of Baudot ITA2 (notice the QWERTYUIOP/1234567890) to make 0–9 punch their values.

jgrahamc 4y ago
Yes. But why that permutation? And although there is a relationship (like Q and 1 being on the same key) there isn't a relationship with Baudot or ITA2 (e.g. Q/1 isn't 00001 it's 11101).
- kps 4y ago
  In case you're not already aware (and/or for readers who aren't, because I wasn't yesterday), they made substantial modifications to Model 15 Teletypes to get their chosen coding and key layout (numeric-pad-like rather than QWERTY), including modifying and permuting levers, type bars, and keycaps. It could be that KSNJFL was somehow most convenient in that respect, though it's hard to imagine. https://archive.org/details/modificationofte56mill https://archive.org/details/modificationofte56mill
  - jgrahamc 4y ago
    Yeah. It's pretty interesting because they clearly did this super intentionally. As you say they moved everything around. Since they are using the existing keycaps which have Q/1, W/2 etc. they lose QWERTYUIOP but they've still got ASDFGHJKLZXCVBNM from which to get the hex digits. The one clue I haven't explored deeply is that there are references to ORDVAC and ILLIAC I using the same teletype equipment as prepared for the Institute of Advanced Study (IAS) Machine (i.e. von Neumann's machine). These machines all have the same principles and it's possible that these teletypes (prepared by the US Bureau of Standards) are the source of KSNJFL.