Simon was a relay-based computer, described by
Edmund Berkeley in a series of thirteen construction articles in ''
Radio-Electronics'' 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 tech ...
",
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 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 buildings ...
was based on relays. The programs ran from a standard paper tape, with five rows of holes for data. The registers and ALU
ALU, Alu or alu may refer to:
Computing and science
;Computing
*Arithmetic logic unit, a digital electronic circuit
;Biology
* Alu sequence, a type of short stretch of DNA
*'' Arthrobacter luteus'', a bacterium
Organizations
* Abraham Lincoln ...
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 represented a ...
s. The user entered data via punched paper, or by five keys on the front panel. 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, 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