IBM's 1948 vacuum-tube flip-flop: a 1-bit memory in a pluggable module
Energizing a vacuum-tube flip-flop module from a 1948 IBM system
In 1948, IBM's 604 Electronic Calculating Punch used vacuum tubes to process punch cards at 100 per minute. A key component was the TR-3 trigger module, a pluggable unit containing a dual-triode tube that formed a flip-flop—a circuit storing one bit. This article reverse-engineers the module, explains the tube's operation, and shows how two cross-coupled inverters create a stable state. The author powered it up, demonstrating the flip-flop's behavior with neon bulbs.
The trigger is a circuit with two states—on and off—and can be switched from one state to the other, providing one bit of temporary storage.
- brudgers
Parallel discussion, https://news.ycombinator.com/item?id=49125602
- SoftTalker
I love the ad copy from 1951. Sounds like how people talk about AI today.
"No longer must valuable engineering personnel ... now in critical shortage ... spend priceless creative time at routine repetitive figuring"