Maybe I'm misremembering (I was very young) or maybe I was with people who were too superstitious, but these tubes themselves were actually from the 1950s, and

Maybe I'm misremembering (I was very young) or maybe I was with people who were too superstitious, but these tubes themselves were actually from the 1950s, and they did indeed take a significant amount of time before they decided the hardware was "warm enough" that one could let the software start doing its thing.