[yaakov34]

Like I said - people say this all the time, but a lot of vacuum tube equipment did die in EMP testing (in the USSR in 1964), and I don't see why vacuum tubes should be less vulnerable than solid state electronics to either short or long pulses (nuclear EMP contains both). A glass vacuum tube will pick up orders of magnitude more interference than a small transistor sitting inside its grounded metal can (and it's weight-prohibitive to build a metal shield around all your vacuum tubes), and the high voltage induced can damage either the vacuum tube itself, or something else inside the device. Unfortunately, very little has been published on this (although we do know that militaries test their modern solid-state devices with EMP, and they generally pass), and any online search produces a deluge of statements to the effect of "vacuum tubes are impervious to EMP" without anything to back that up. If there was ever a direct test of vacuum tubes vs. solid state, that would be very interesting to find.

[nickff]

Transistors of the 1950s and 1960s were particularly vulnerable to high voltages. Modern transistors and ICs have some resistance to high voltage discharges such as static electricity, but back in those days, you could easily destroy entire circuits with your hand. Early transistors were made with materials and processes we would consider sub-standard today, which is particularly significant because they were almost exclusively using bipolars instead of MOSFETs (which are much more durable), and the manufacturers of the 60s could not and did not add protection diodes. ESD control was one reason why certain American companies got so far ahead of the Soviets (and the less-adaptable competition such as Phillips, whose workforce refused to adopt ESD control practices).

[yaakov34]

True, and electrostatic discharge from your finger is no joke - it can be tens of kilovolts and carries significant, if not huge, energy. However, a discharge like that going right into a very small device, and the actual die of the transistor is tiny, is very different from interference/EMP damaging said device, where the small size actually offers protection. After all, a completed transistorized device from the 1950s is not vulnerable to static discharge - otherwise, you couldn't pick it up. With everything connected to ground where it should be, it is quite robust.

[nickff]

Modern ICs are much more durable and resistant to ESD than devices from those days; you can run an electronics manufacturing facility (not a semiconductor fab) without much ESD protection these days, whereas that would've been a pipe-dream in the 60s. They are sending consumer and commercial-grade semiconductors into space on satellites with service lives over 12 months these days; back in the 1960s, all satellites required rad-hard components (and had very short service lives). Semiconductors are much better these days, due to improvements in materials, processes, testing, and inspection equipment.