ENIAC: Verskil tussen weergawes

'''ENIAC''', Engels vir '''Electronic Numerical Integrator And Computer''',<ref>{{cite book | last = Goldstine | first = Herman H. | authorlink = Herman Goldstine | title = The Computer: from Pascal to von Neumann | year = 1972 | publisher = Princeton University Press | location = Princeton, New Jersey | id = ISBN 0-691-02367-0 }}</ref> was die eerste algemeen doelgerigte elektroniese rekenaar. Dit was die eerste hoë-spoed, [[Turingvolledigheid|Turingvolledige]], digitale rekenaar wat herprogrammeer kon word om 'n reeks rekenkundige probleme op te los, <ref>Shurkin, Joel, ''Engines of the Mind: The Evolution of the Computer from Mainframes to Microprocessors'', 1996, ISBN 0-393-31471-5</ref> terwyl vroëre masjiene net sekere van die eienskappe gehad het. Die ENIAC was ontwerp en gebou deur die [[VSA]]-weermag om artillerie vuur tabelle te bereken.

 

Die konstruksie kontrak was geteken op [[5 Junie]], [[1943]], en werk op die rekenaar het, die volgende maand, in die geheim begin onder die skuilnaam "Projek PX" deur die [[Universiteit van Pennsylvania]] se [[Moore Skool van Elektriese Ingenieurswese]]. Die volledige masjien was onthul op [[14 Februarie]], [[1946]] by die Universiteit van Pennsylvania, en het $500,000 gekos. Dit is formeel deur die V.S. Weermag Artillerie afdeling in diens geneem in Julie 1946. ENIAC was afgeskakel op [[9 November]], [[1946]] vir opknappings en 'n geheue opgradering, en was geskuif na [[Aberdeen Toets Grond]], [[Maryland]] in 1947. Daar, op [[29 Julie]], [[1947]], is dit weer aangeskakel en was in voortdurende gebruik tot 11:45 pm, [[2 Oktober]], [[1955]].

 

 

 

}}</ref> Die span ontwerp ingenieurs wat die ontwikkeling bygestaan en gehelp het sluit in [[Robert F. Shaw|Bob Shaw]] (funksie tabelle), [[Chuan Chu]] (deler/vierkantswortelaar), [[Kite Sharpless]] (meester programmeerder), [[Arthur Burks]] (vermenigvuldiger), [[Harry Huskey]] (leser/drukker, [[Jack Davis (ingenieur)|Jack Davis]] (versamelaars) en [[Iredell Eachus Jr.]]<ref>{{cite web| url=http://www.upenn.edu/gazette/0506/obits.html | title=Gazette Alumni: Obituaries (Iredell Eachus Jr.) | toegangsdatum=2008-09-11 | quote=According to his family, J. Presper Eckert EE’41 GEE’43 Hon’64 was his best friend in college. As a U.S. Naval ensign during World War II, he received a direct commission from President [[Franklin D. Roosevelt]] assigning him to naval-research work in Washington, where he was involved in developing technology for weapons systems, radar targeting systems, and communications devices. He then became a member of the ENIAC team at Penn. According to the Main Line Times, he felt that the logic circuits of the machine were more discovered than invented. }}</ref>

 

Die ENIAC was 'n modulere [[rekenaar]], saamgestel uit individuele panele om verskillende funksies te verrig. Twintig van hierdie modules was versamelaars, wat nie net kon optel en aftrek nie, maar kon ook 'n tien-syfer [[desimale]] nommer stoor in sy geheue. Nommers was aangegee tussen twee eenhede oor 'n aantal algemeen-doelige busse, of borde, soos dit genoem was. Om die hoë spoed te bereik moes die panele die nommers ontvang en aanstuur, bereken, die antwoord stoor, en die volgende stap aktiveer&nbsp;- alles sonder bewegende onderdele. Die sleutel tot sy veelsydigheid was die vermo&euml; om te vertak; dit kon verskillende bewerkings, wat afhanklik was van die berekende resultaat, aktiveer

 

 

The other nine units in ENIAC were the ''Initiating Unit'' (which started and stopped the machine), the ''Cycling Unit'' (used for synchronizing the other units), the ''Master Programmer'' (which controlled 'loop' sequencing), the ''Reader'' (which controlled an IBM punch card reader), the ''Printer'' (which controlled an IBM punch card punch), the ''Constant Transmitter'', and three ''Function Tables''.

 

The references by Rojas and Hashagen or (Wilkes 1956)<ref name="autogenerated1">Wilkes</ref> give more details about the times for operations, which differ somewhat from those stated above. The basic machine cycle was 200 [[microseconds]] (20 cycles of the 100&nbsp;kHz clock in the cycling unit), or 5,000 cycles per second for operations on the 10-digit numbers. In one of these cycles, ENIAC could write a number to a register, read a number from a register, or add/subtract two numbers. A multiplication of a 10-digit number by a ''d''-digit number (for ''d'' up to 10) took ''d''+4 cycles, so a 10- by 10-digit multiplication took 14 cycles, or 2800 microseconds—a rate of 357 per second. If one of the numbers had fewer than 10 digits, the operation was faster. Division and square roots took 13(''d''+1) cycles, where ''d'' is the number of digits in the result (quotient or square root). So a division or square root took up to 143 cycles, or 28,600 microseconds—a rate of 35 per second. (Wilkes 1956:20<ref name="autogenerated1" /> states that a division with a 10 digit quotient required 6 milliseconds.) If the result had fewer than ten digits, it was obtained faster.

 

ENIAC used common [[tube socket#Octal|octal-base]] radio tubes of the day; the decimal [[Accumulator (computing)|accumulators]] were made of [[6SN7]] [[flip-flop (electronics)|flip-flops]], while 6L7s, 6SJ7s, 6SA7s and 6AC7s were used in logic functions. Numerous [[6L6]]s and [[6V6]]s served as line drivers to drive pulses through cables between rack assemblies.

 

 

[[Kategorie:Geskiedenis van die rekenaar]]