June 7, 2026
Tube drama, but make it vintage
Powering up a module from the IBM 604: an electronic calculator from 1948
This 1948 giant just lit a bulb, and the comments are losing it over how weirdly smart it was
TLDR: Ken Shirriff powered up a plug-in part from IBM’s 1948 calculator, showing how early business machines used smart, swappable components long before modern gadgets. Commenters were charmed, impressed, and very online about it—mixing awe, dry jokes, and a little IBM roast history.
A 1948 IBM calculator module getting powered up in 2026 should be a niche history flex, but the real show is the comment section turning into a retro-tech fan club with punch cards. On Ken Shirriff’s blog, the restored chunk of the IBM 604—a business machine from the late 1940s—comes back to life and controls a light bulb. That may sound small now, but back then this was a big deal: a machine businesses could actually rent, use, and fix, instead of a room-sized science project for governments and universities.
The strongest reaction? Pure amazement that something this old was already so modular, meaning built from swappable parts like chunky tech Lego. One commenter flat-out said they’d never seen tubes packaged with their support parts in one plug-in unit before, calling it "clever" because repairs would be faster. Another marveled at how few vacuum tubes these early machines used compared with the absurd number of tiny switches inside modern chips. Translation for normal people: the crowd is basically saying, “Wait, 1948 hardware was both simpler and smarter than I expected?”
There was also some delightful nerd-comedy. One user deadpanned at the line “1948 was an interesting time for computing,” joking that this is not a commonly seen statement—the kind of dry humor that lands perfectly in a room full of computer-history obsessives. And then came the veteran lore-drop: one commenter rolled in with a mini saga of IBM’s earlier machines, including the savage nickname for the 602A: “a 602 that worked.” Honestly, that one line brought more drama than most product launches.
Key Points
- •The article places the IBM 604 within the rapid transition from electromechanical to electronic computing around 1948.
- •IBM’s 604 was a programmable calculator rather than a general-purpose computer, but it was smaller, cheaper, and fast enough to perform 60 operations in under a second.
- •The IBM 604 became widely adopted, with more than 5,600 units produced, and helped build IBM’s expertise in vacuum-tube computing.
- •A key innovation was the pluggable module that combined a vacuum tube with associated resistors and capacitors in a replaceable unit.
- •The featured module uses a thyratron tube acting as a high-current switch, and the author demonstrated it by powering a light bulb in a test circuit.