A serial computer is a computer typified by bit-serial architecture — i.e., internally operating on one bit or digit for each clock cycle. Machines with serial main storage devices such as acoustic or magnetostrictive delay lines and rotating magnetic devices were usually serial computers.
Serial computers required much less hardware than their parallel counterpart, but were much slower.
Serial machines
The first computer that was not serial (the first parallel computer) was the Whirlwind — 1951.
Most of the early massive parallel processing machines were built out of individual serial processors, including:
References
Serial computer Wikipedia(Text) CC BY-SA