{{Short description|Computer with a bit-serial architecture}} {{Use dmy dates|date=April 2022|cs1-dates=y}} {{Use list-defined references|date=June 2022}} A '''serial computer''' is a computer typified by bit-serial architecture{{snd}} 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 bit-parallel counterparts<ref name="Wilkes_1956"/> which exploit bit-level parallelism to do more computation per clock cycle. There are modern variants of the serial computer available as a soft microprocessor<ref name="Howe_2019"/> which can serve niche purposes where the size of the CPU is the main constraint.
The first computer that was not serial and used a parallel bus 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 152{{Citation needed|date=April 2020}} (1954) * Bendix G-15 (1956) * LGP-30 (1956)<ref name="Miller_1966"/> * Elliott Brothers Elliott 803 (1958) * ZEBRA{{Citation needed|date=April 2020}} (1958) * D-17B guidance computer (1962) * PDP-8/S<ref name="DEC_1978"/> (1966) * General Electric GE-PAC 4040 process control computer * F-14 CADC (1970) {{snd}} transferred all data serially, but internally operated on many bits in parallel<ref name="Holt_1971"/> * Kenbak-1 (1971) * Datapoint 2200 (1971)<ref name="Shirriff_2015"/> * HP-35 (1972)<ref name="Stone_1975"/> * Digit-serial HP Saturn-based calculators<ref name="Smith_2023"/> from the HP-71B (1974) to the HP 50g (2006–2015) * National Semiconductor SC/MP (1976) * Ferranti F100-L (1977) {{snd}} 16-bit, but uses a bit-serial arithmetic logic unit
=== 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-1 (1990) {{snd}} 32-bit architecture, internally processed 4 bits at a time<ref name="Culver_2014"/> * VIRAM1 computational RAM (2003)
== See also == * 1-bit computing * BKM algorithm * CORDIC algorithm
== References == <references>
<ref name="DEC_1978">{{cite book |title=Nineteen Fifty-Seven to the Present |date=1978 |orig-date=1972 |edition=6 |publisher=Digital Equipment Corporation |location=Maynard, Massachusetts, USA |page=7 |url=http://www.bitsavers.org/pdf/dec/_Books/DEC_1957_To_The_Present_1978.pdf |access-date=2021-02-06 |url-status=live |archive-url=https://web.archive.org/web/20220302210148/http://bitsavers.org/pdf/dec/_Books/DEC_1957_To_The_Present_1978.pdf |archive-date=2022-03-02}} (1+viii+87+3 pages)</ref> <ref name="Miller_1966">{{cite book |title=Switching Theory – Volume 1: Combinational Circuits |author-first=Raymond E. |author-last=Miller |date=1965 |edition=Second printing, March 1966, of 1st |lccn=65-14249 |volume=1 |publisher=John Wiley & Sons, Inc. |pages=44–47}}</ref> <ref name="Wilkes_1956">{{cite book |title=Automatic digital computers |author-last=Wilkes |author-first=Maurice Vincent |author-link=Maurice Vincent Wilkes |date=1956 |publisher=Methuen Publishing Ltd / John Wiley & Sons, Inc. |url=https://books.google.com/books?id=1vUrAAAAIAAJ |access-date=2012-06-06}}</ref> <ref name="Holt_1971">{{cite book |title=This paper describes the architecture of the CPU and Memory for the Central Air Data Computer (CADC) System used in the Grumman/Navy F14A carrier-based fighter aircraft. |author-first=Raymond M. |author-last=Holt |author-link=Raymond M. Holt |date=1971 |id=AP1-26-97 |pages=5, 7 |url=http://firstmicroprocessor.com/documents/ap1-26-97.pdf |access-date=2017-11-04 |url-status=deviated |archive-url=https://web.archive.org/web/20171104082502/http://firstmicroprocessor.com/documents/ap1-26-97.pdf |archive-date=2017-11-04 |quote=[…] the processor was designed to transfer data serially throughout the entire system. […] The Parallel Multiplier Unit […] by means of a parallel algorithm […]}} (26 pages)</ref> <ref name="Howe_2019">{{cite web |title=Bit-Serial: A bit-serial CPU written in VHDL, with a simulator written in C. |author-last=Howe |author-first=Richard James |date=2020 |orig-date=2019-06-27 |website=Github Project: A Bit Serial CPU |url=https://github.com/howerj/bit-serial |access-date=2019-06-28 |url-status=live |archive-url=https://web.archive.org/web/20220615231144/https://github.com/howerj/bit-serial |archive-date=2022-06-15}} </ref> <ref name="Shirriff_2015">{{cite web |title=The Texas Instruments TMX 1795: the (almost) first, forgotten microprocessor |author-first=Ken |author-last=Shirriff |date=May 2015 |url=https://www.righto.com/2015/05/the-texas-instruments-tmx-1795-first.html |access-date=2020-05-29 |url-status=live |archive-url=https://web.archive.org/web/20220615173952/https://www.righto.com/2015/05/the-texas-instruments-tmx-1795-first.html |archive-date=2022-06-15 |quote=Even operating one bit at a time as a serial computer, the Datapoint 2200 performed considerably faster than the 8008 chip...}}</ref> <ref name="Culver_2014">{{cite web |title=MasPar: Massively Parallel Computers – 32 cores on a chip |date=2014-09-05 |author-first=John |author-last=Culver |url=http://www.cpushack.com/2014/09/05/maspar-massively-parallel-computers-32-cores-on-a-chip/ |access-date=2022-06-15 |url-status=live |archive-url=https://web.archive.org/web/20220615173816/https://www.cpushack.com/2014/09/05/maspar-massively-parallel-computers-32-cores-on-a-chip/ |archive-date=2022-06-15}}</ref> <ref name="Smith_2023">{{cite web |title=HP-15C CE woes: 1 bug, 2 limitations, 3 questions |author-first=Eric L. "Brouhaha" |author-last=Smith |date=2023-08-09 |work=MoHPC - The Museum of HP Calculators |url=https://www.hpmuseum.org/forum/thread-20281.html |access-date=2023-09-24 |url-status=live |archive-url=https://web.archive.org/web/20230810144726/https://www.hpmuseum.org/forum/thread-20281.html |archive-date=2023-08-10}}</ref> <ref name="Stone_1975">{{cite book |title=Introduction to Computer Architecture |author-first=Thomas M. |author-last=Whitney |author-link=Thomas Whitney (computing) |editor-first=Harold Stuart |editor-last=Stone |editor-link=Harold Stuart Stone |date=1975 |edition=1 |chapter=Part I. Basic Computer Architecture. / Chapter 3. Introduction to Calculators: / 3-5. Example Systems / The Hewlett Packard HP-35 |series=Computer Sciences Series |publisher=Science Research Associates, Inc. (SRA) |publication-place= |id=ark:/13960/t8pc40t3q. Order-Code 13-4005 |lccn=75-14016 |isbn=0-574-18405-8 |pages=118–135 [123–135] |chapter-url=https://archive.org/details/introductiontoco00ston/page/123/mode/2up?view=theater |access-date=2023-09-29 |quote-page=124 |quote=[…] The HP-35 is a totally serial computer. The adder is a BCD serial type […] The serial structure means less integrated circuit area must be allocated to interconnection lines and gating functions and an interesting trade off occurs. A bit-serial, digit-serial architecture is inherently one fourth the speed of a bit-parallel digit-serial structure […] But the basic clock rate for a bit-serial structure can sometimes be increased since additional area can be allocated for larger integrated devices that are necessary for greater speed. In the HP-35, the execution time of the most complex functions is under one second, while the serial architecture permits an increased circuit complexity. […] Instructions in the HP-35 are transferred serially from the active read-only memory to the arithmetic and control circuits and to other ROMs if present. […]}}</ref>
</references>
== Further reading == * {{cite book |title=Digit-Serial Computation |author-first1=Richard I. |author-last1=Hartley |author-link1=Richard I. Hartley |author-first2=Keshab K. |author-last2=Parhi |publisher=Kluwer Academic Publishers |date=1995 |edition=1 |isbn=0-7923-9573-5 |id=SECS316 |series=The Kluwer International Series in Engineering and Computer Science |publication-place=Norwell, Massachusetts, USA}} (xiv+306 pages) * {{cite journal |title=A Systematic Approach for Design of Digit-Serial Signal Processing Architectures |author-last=Parhi |author-first=Keshab K. |journal=IEEE Transactions on Circuits and Systems |issn= |volume=38 |number=4 |date=April 1991 |pages=358–375 |doi=10.1109/31.75394 |bibcode=1991ITCS...38..358P }} (8 pages)
Category:Classes of computers *Serial computers Category:Serial computers