Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!rutgers!aramis.rutgers.edu!porthos.rutgers.edu!webber From: webber@porthos.rutgers.edu (Bob Webber) Newsgroups: comp.arch Subject: Re: ENIAC Query Message-ID: Date: 12 Nov 89 04:03:50 GMT References: <38193@lll-winken.LLNL.GOV> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 40 In article <38193@lll-winken.LLNL.GOV>, berry@lll-crg.llnl.gov (Berry Kercheval) writes: > > Anyone know what *kind* of vacuum tubes ENIAC used? Were they 6SN7's? In The ENIAC: First General-Purpose Electronic Computer Arthur W. Burks and Alice R. Burks Annals of the History of Computing, Volume 3, Number 4, October 1981, 310 -- 398 some circuit diagrams from the ENIAC are reproduced (Figures 14, 15, and 19). The labelled tubes in these diagrams are: Simplified accumulator program-control circuit: 6SN7, 6L6, 6V6, 6SA7, and 6J5. Decade counter: 6L6, 6SN7, and 6Y6 Multiplication table: 6L6 and 6L7 In: From ENIAC to UNIVAC: An Appraisal of the Eckert-Mauchly Computers Nancy Stern Digital Press, 1981 there is mention of the tubes being from RCA and on page 32 is a reproduction of the Summary of Tube Failure in ENIAC from: Tube Failures in ENIAC F. Robert Michaels Electronics, October 1947 which lists the following breakdown of tube type in the ENIAC: 6,550 6SN7 Twin Triode 4,200 6L6 Beam Power 2,600 6SA7 Pentagrid Converter 1,500 6SJ7 Triple Grid Amplifier 1,300 6V6 Beam Power 1,200 6L7 Pentagrid Mixer 500 6AC7 Television Pentode 350 807 (Enlarged 6L6) 300 6J5 Dectector Triode 300 6Y6 Beam Power [this totals to 18,800 (most articles on the ENIAC speak of there being 18,000 vacumn tubes, so this probably accounts for everything).] --- BOB (webber@athos.rutgers.edu ; rutgers!athos.rutgers.edu!webber)