John Attanasoff was born in 1903 and invented his Version of the Computer. In 1939 Attanasoff began his construction of the ABC alongside Clifford Berry, an engineering student he hired to help. Unfortunately, some equations were failing and before they could resolve it, they were both sent off to fight in WW2.
As a result, in 1948 Attanasoff found that their machine had been dismantled and removed. The only part left was one of the memory drums. This was the first computer to use RAM and could do 30 simultaneous operations.
A team from Iowa State University, between 1992 and 1997 rebuilt the ABC which is now displayed in the California Computer History Museum. A lot of the ideas from the ABC were later used in the development of the ‘ENIAC’, the first general purpose computer.