Serial computer
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 require much less hardware than their parallel computing counterpart, but are much slower. There are modern variants of the serial computer available as a soft microprocessor which can serve niche purposes where size of the CPU is the main constraint.

The first computer that was not serial (the first parallel computer) was the Whirlwind in 1951.

A serial computer is not necessarily the same as a computer with a 1-bit architecture, which is a subset of the serial computer class. 1-bit computer instructions operate on data consisting of single bits, whereas a serial computer can operate on N-bit data widths, but does so a single bit at a time.

Serial machines 
 EDVAC 1949
 BINAC 1949
 SEAC 1950
 UNIVAC I 1951
 Elliott Brothers Elliott 153 1954
 Bendix G-15 1956
 LGP-30 1956
 Elliott Brothers Elliott 803 1958
 ZEBRA 1958
 D-17B guidance computer 1962
 PDP-8/S 1966
 General Electric GE-PAC 4040 process control computer
 Datapoint 2200 1971
 F14 CADC 1970: transferred all data serially, but internally operated on many bits in parallel.
 HP-35 1972

Massively parallel 
Most of the early massive parallel processing machines were built out of individual serial processors, including:
 ICL Distributed Array Processor 1979
 Goodyear MPP 1983
 Connection Machine CM-1 1985
 Connection Machine CM-2 1987
 MasPar MP-11990 (32-bit architecture, internally processed 4 bits at a time)
 VIRAM1 computational RAM 2003

See also 
 1-bit computing

References 

Classes of computers
Serial computers