22 votes

Was the IBM 5100 ever used for codebreaking?

The 5100 had programmable microcode which could be used to implement crypto-specific opcodes1,2,3. Then there's the whole John Titor4,5 thing... 1 Such as population count 2 I'm unaware of anyone ...
  • 9,050
8 votes

Was the IBM 5100 ever used for codebreaking?

I think the original argument (both in the John Titor hoax and in Steins;Gate) goes like this: The IBM 5100 can emulate the IBM mainframe ISA (that's true, and that's how the APL running on the IBM ...
  • 22.2k
3 votes

Was the IBM 5100 ever used for codebreaking?

I have an IBM 5100. There were some versions with APL-only and some versions with BASIC-only, while also yet another version that did have "the switch" as mentioned to toggle between either ...
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1 vote

Was the IBM 5100 ever used for codebreaking?

Apologies, this didn't occur to me in my earlier Reply: There is also one other special feature of the IBM 5100. A long time ago with typewriters, you could backspace, and "overstruck" a new ...
  • 129

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