With regards to the more advanced tubes (tetrodes, pentodes, etc) Was there any experimentation with integrated circuits before transistors took over? Put 10 tubes in the same enclosure, 100.
I am imagining something like a vacuum florescent display but with logic instead of display elements.
I think solid state technology came too soon for the miniaturization of vacuum tube technology to be fully explored. Ken mentions in one of his older posts that even in these old tube-based IBM computers a lot of digital logic was in fact already done with semiconductor diodes, not vacuum tubes. Optimizations like the nuvistors never took off because semiconductors were already more economic.
I guess you could do a whole circuit on photo-etched or stamped sheet metal inside a glass envelope in a similar process that VFDs, although I don't know how you would implement cathode heating. It would be an interesting exercise to think where that could lead you, but I think modern VFDs date much later, when semiconductors already wholly replaced tubes in digital logic.
What fails in a tube is usually the heater filament, which is a wear part with a limited life. Where some (very) expensive tubes did go is to have replaceable heaters - so not more but less integration.
Fantastic deep dive as always, thanks for doing such stellar work!
On that note, any chance we might get a teardown/history of Cray architectures in the future? Specifically the Cray-1 and 2?
To throw a more serious challenge your way: How about a write-up on the original Frank Rosenblatt Perceptron? I know finding an original Mark-1 part would be close to impossible but it blows my mind that they were successfully doing real-time visual classification in 1957 with an electro-mechanical machine (potentiometers and motors) using a 20x20 "video" feed with some learning algorithm that was not based on backprop.
Univac had similar single-tube modules (but without the handle), as well as multiple-tube modules. See this video: https://www.youtube.com/watch?v=NVbjXHR6WAY
The BRLESC computer used printed-circuit boards that had components and a single tube (parallel to the surface). I have a Burroughs module with 8 tubes.
Philbrick op amp K2-W was an analog circuit with two dual-triode tubes on top of circuitry, with an octal plug at the bottom. I have one with data sheet but have never fired it up.
Roughly how many varieties of module were used for a full 604 system?
I suspect quite a few as other "modular" systems in the transistor era like the later IBM Standard Modular System and DEC Flip-Chips ended up with plethora of specialised modules, but I'd be interested if that growth had already begun in the tube era.
I don't have the information for the 604, but the 605 used about 36 different types of tube modules. IBM couldn't resist making different types of modules; the 650 had sixteen types of cathode followers alone.
I am imagining something like a vacuum florescent display but with logic instead of display elements.