Transistors
By the 1950's transistors were becoming more available which offered the possibility of building faster and cheaper computers while less reliable than vacuum tubes they ran much lower temperatures and were much smaller in size they also cost less to make and operate and they used less energy. When Bipolar Junction Transistors were put into
But First...
Before the first fully electronic computer there was such thing as computers they just weren't fully electric, they were partially electronic and partially mechanical, Konrad Zuse created the first line of computers the Z-series, this line included Zuse Z1, Z2, Z3, and Z4, the Z1 being constructed in 1936. Zuses research and development were acctually funded by IBM in return for an option on his patents.
And then Came the Colossus
Colossus was the next big thing in computers this time being developed by the British and was used mainly to decipher German communications, there were a total of nine of these colossi built and the original was converted into two seperate computers, the details of their exsistence, design and use were kept secret until well into the 1970's. Winston Churchill personally ordered the computers and designs destroyed to keep the details a secret.