The
first, called the Complex Computer, employing over 9,000
telephone relays, was completed in 1940. Used for multiplication
and division of complex numbers, it could perform one
addition of subtraction every three tenths of a second.
Programming
instructions and routines were entered via paper tape.
The system had a form of time-sharing. Six Teletype units
could be hooked to a computer to enter or print data.
The system could handle multiprocessing by combining a
number of computers to solve several problems concurrently.