Simon was a relay-based computer, described by
Edmund Berkeley
Edmund Callis Berkeley (February 22, 1909 – March 7, 1988) was an American computer scientist who co-founded the Association for Computing Machinery (ACM) in 1947. His 1949 book ''Giant Brains, or Machines That Think'' popularized cognitiv ...
in a series of thirteen construction articles in ''
Radio-Electronics
''Radio-Electronics'' was an American electronics magazine that was published under various titles from 1929 to 2003. Hugo Gernsback, sometimes called the father of science fiction, started it as ''Radio-Craft'' in July 1929. The title was changed ...
'' magazine, from October 1950. Intended for the educational purpose of demonstrating the concept of digital computer, it could not be used for any significant practical computation since it had only two bits of memory. In 1950, it sold for
US$600. Some have described it as the "first
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...
",
What was the first personal computer?
at ''Blinkenlights Archaeological Institute''. Accessed: March 15, 2008. although its extremely limited capacity and its unsuitability for use for any purpose other than as an educational demonstration make that classification questionable.
History
The "Simon project" arose as a result of the Berkeley's book ''Giant Brains, or Machines That Think'', published in November 1949. There, the author said:
:
In November 1950, Berkeley wrote an article titled ''Simple Simon'' for ''Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...
'' magazine,[
] that described digital computing
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These pro ...
principles to the general public. Despite Simon's extreme lack of resources (it could only represent the numbers 0, 1, 2 and 3), Berkeley stated on page 40 that the machine ''"possessed the two unique properties that define any true mechanical brain: it can transfer information automatically from any one of its "registers" to any other, and it can perform reasoning operations of indefinite length."'' Berkeley concluded his article anticipating the future:
Technical specifications
The Simon's architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing building ...
was based on relay
A relay
Electromechanical relay schematic showing a control coil, four pairs of normally open and one pair of normally closed contacts
An automotive-style miniature relay with the dust cover taken off
A relay is an electrically operated switch ...
s. The programs ran from a standard paper tape, with five rows of holes for data. The registers and ALU stored only 2 bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
s. The user entered data via punched paper, or by five keys on the front panel
A front panel was used on early electronic computers to display and allow the alteration of the state of the machine's internal registers and memory. The front panel usually consisted of arrays of indicator lamps, digit and symbol displays, to ...
. The machine output data through five lamps.
The punched tape served not only for data entry, but also as memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...
storage. The machine executed instructions in sequence, as it read them from the tape. It could perform four operations: addition, negation, greater than
In mathematics, an inequality is a relation which makes a non-equal comparison between two numbers or other mathematical expressions. It is used most often to compare two numbers on the number line by their size. There are several different n ...
, and selection.
Notes
External links
Simon's FAQ
* {{cite web, title=VintageComputer.net - Simon {{! Mechanical Computer {{! Early Analog Desktop Computers 1950 {{! Radio-Electronics October 1950 {{! Edmund C. Berkeley {{! Robert A Jensen {{! Vintage Computers {{! First Desktop Computer, url=http://www.vintagecomputer.net/simon.cfm, website=www.vintagecomputer.net
Edmund C. Berkeley Papers
Charles Babbage Institute
The IT History Society (ITHS) is an organization that supports the history and scholarship of information technology by encouraging, fostering, and facilitating archival and historical research. Formerly known as the Charles Babbage Foundation, ...
, University of Minnesota. Box 22 has correspondence, memos, accounting records, and notes on the development and marketing of small robots, including Relay Moe, Franken, Tit-Tat-Toe Machine, Test Your Nerve Machine, Simon, and mechanical brain kits.
Electro-mechanical computers
1950s computers
Computer-related introductions in 1950