It used 5200 vacuum tubes.
Millman's theorem
You don't, there aren't any. However some radios in the early 1950s did use both vacuum tubes and transistors. This was because early junction transistors were too slow to operate at RF so vacuum tubes were used in the RF and IF sections. These radios were called hybrid radios because they used both vacuum tubes and transistors.
ENIAC
First generation computers.
FIRST GENERATION
first generation computers
Vacuum tubes still find uses where solid-state devices have not been developed, are impractical, or where a tube has superior performance, as with some devices in professional audio and high-power radio transmitters. Tubes are still produced for such applications.
Vacuum tubes were used back in the 19th century and mid-20th century for a number of things. At first they were used just in scientific areas, but then they were used as electronic amplifiers. They were eventually used in the first computers.
red lights, lasers, vacuum tubes, some TV tubes, etc.
No, he had to use mechanical gears, etc. because they were the only device technology available in his time. Electric relays were first developed about 15 years after he designed his computer, while vacuum tubes were first developed about 90 years after he designed his computer.
No, unless you are still using a CRT monitor.