Powering Up a 1948 IBM 604 Vacuum Tube Flip-Flop Module

Energizing a vacuum-tube flip-flop module from a 1948 IBM system

Powering Up a 1948 IBM 604 Vacuum Tube Flip-Flop Module

I reverse-engineered and powered up a TR-3 trigger module from the 1948 IBM 604 Electronic Calculating Punch. This vintage component used a 2033 dual triode vacuum tube to store one bit of data as a flip-flop. By analyzing the circuitry and testing the module, I demonstrated how these early electronic components functioned as essential building blocks for computation before the transistor era.

This might appear trivial, but the ability to store information is vitally important for computation.
  1. kens

    Author here. I've powered up another tube module from the IBM 604, so let me know if you have questions...

  2. CaliforniaKarl

    What was the failure rate of those vacuum tubes, that they had to be so quick & easy to replace?

    I'm also curious, if the cathode was grounded to the machine frame, how dangerous was it to do work on those machines?

  3. ck2

    integrated circuits were only invented a couple years before the Apollo moon missions started in 1961

    imagine an alternate timeline where that didn't happen, could moon landing have even happened with vacuum-tubes? highly unlikely

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2026-08-05