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Vacuum Tube

In 1946 two Americans, Presper Eckert, and John Mauchly built the ENIAC electronic computer which used vacuum tubes instead of the mechanical switches of their predecessors.  The ENIAC used thousands of vacuum tubes, which took up a lot of space and gave off a great deal of heat just like light bulbs do.  The ENIAC led to other vacuum tube type computers like the EDVAC (Electronic Discrete Variable Automatic Computer) and the UNIVAC I (UNIVersal Automatic Computer).

The vacuum tube was an extremely important step in the advancement of computers.  Vacuum tubes were invented the same time the light bulb was invented by Thomas Edison and worked very similar to light bulbs.  It's purpose was to act like an amplifier and a switch.  Without any moving parts, vacuum tubes could take very weak signals and make the signal stronger (amplify it).  Vacuum tubes could also stop and start the flow of electricity instantly (switch).  These two properties made the ENIAC computer possible.

 

 The history of the vacuum tube can be traced to Tomas Edison.

In 1879 Edison exhibited his incandescent electric light bulb for the first time.

Using vacuum tubes, The ENIAC gave off so much heat that they had to be cooled by gigantic air conditioners.  However even with these huge coolers, vacuum tubes still overheated regularly.  It was time for something new.