Digi-Comp I
The Digi-Comp I is a functioning, mechanical digital computer sold in kit form. It was originally manufactured from polystyrene parts by E.S.R., Inc. starting in 1963 and sold as an educational toy for US$4.99 ({{Inflation|US|4.99|1963|fmt=eq|cursign=US$}}).{{cite web|url=https://www.syssrc.com/digicomp_I_Ad.png|title=Electronic Computer Brain|archive-url=https://web.archive.org/web/20171211190059/https://www.syssrc.com/digicomp_I_Ad.png|archive-date=2017-12-11}}
The Digi-Comp I has been referred to as the first home computer.{{Cite journal |last=Winkless |first=Nelson |date=November 1984 |title=The First Home Computer |journal=Creative Computing |pages=12}}
A successor, the Digi-Comp II, is not programmable, but in effect a visible calculator. A two-level Masonite platform with guides serves as the medium for a supply of marbles that rolled down an inclined plane, moving plastic cams as they fell.{{cite web|url=http://tech.groups.yahoo.com/group/friendsofdigicomp/message/2077 |archive-url=https://archive.today/20130630172025/http://tech.groups.yahoo.com/group/friendsofdigicomp/message/2077 |url-status=dead |archive-date=June 30, 2013 |title=Yahoo friendsofdigicomp |date= |accessdate=2013-04-17}}
Operation
The Digi-Comp I contains three mechanical flip-flops, providing an ability to connect them together in a programmable way using thin vertical wires that are either pushed, or blocked from moving, by a number of cylindrical pegs. The whole arrangement is "clocked" by moving a lever back and forth. Different configurations of these cylinders cause the Digi-Comp to compute different Boolean logic operations. With a three binary digit (3-bit) readout of the state of the flip-flops, it could be programmed to demonstrate binary logic, to perform various operations such as addition and subtraction, and to play some simple logic games such as Nim.{{cite web|last1=Woodhouse|first1=Trevor|title=K'nex Computer|url=https://www.youtube.com/watch?v=jkUd9rYkYnA |archive-url=https://ghostarchive.org/varchive/youtube/20211221/jkUd9rYkYnA |archive-date=2021-12-21 |url-status=live|website=YouTube|publisher=Trevor Woodhouse|accessdate=2015-11-15}}{{cbignore}}
Although promotional materials described it as an "actual working digital computer,"
the device is more accurately described as a finite-state machine,
one of the underpinning concepts used to build computers.
Reproductions
{{stack|Image:Digicomp front.png}}
Starting in 2005, Minds-On Toys has made available the Digi-Comp I version 2.0 as a relatively inexpensive binder's board version of the original Digi-Comp, albeit with a much enhanced instruction manual.{{cite web |url=http://mindsontoys.com/kits.htm?dc1_main.htm |title=Minds-On Toys - Kits |date= |accessdate=2013-04-17}}
See also
- Dr. Nim - game based on the computer
- Geniac
- WDR paper computer
- CARDboard Illustrative Aid to Computation
- Turing Tumble, a 2019 mechanical computer inspired by it
- Robert C. Martin, who credits playing with this toy at the age of 12 as being what made him decide to become a programmer for the rest of his life.{{Citation|title=Clean Code - Uncle Bob / Lesson 5|url=https://www.youtube.com/watch?v=sn0aFEMVTpA |archive-url=https://ghostarchive.org/varchive/youtube/20211221/sn0aFEMVTpA |archive-date=2021-12-21 |url-status=live|language=en|access-date=2021-06-23}}{{cbignore}}
- Little man computer
References
{{reflist|1}}
External links
- [http://www.oldcomputermuseum.com/digicomp_1.html The Old Computer Museum] - Collection of old analog, digital and mechanical computers
- [https://archive.today/20130105164329/http://tech.groups.yahoo.com/group/friendsofdigicomp/ Friends of Digi-Comp] - Discussion of this toy. Images, links, manuals and programming information
- [http://www.mindsontoys.com/kits.htm?dc1_main.htm Digi-Comp I v2.0] - Online vendor of working replica kit; historical details
- [https://digicomp-1.appspot.com/ Digi-Comp I Emulator] - Emulator for the original Digi-Comp I written in JavaScript