MDIGITAL COMPUTER Y@EAESSETTER---OFFICE OF NAVAL RESEARCH_ MATHEMATICAL ICIENCES DIVISION Mi t January l0ob TIABILE Or W-NTI•NIV VM ILti tik'NhlvK AlII 't1l 4 Nk J i 4 l h tCAI At' The hWA V lb 1 o NWAt N Whirlwind I A Moore 4 hotel A khsithflh' Ctompute% MNAC 1 I'he hlirrauuhs I abtoratory Compolor 4 Novel P'ro% ng round Ca'liilator IV Aberdeeon l'he The The Provt il t rou•od 't CNIAIC 0RI' VAC 011VAC SPIiCIA1 P'URPOSE5 1 VATA 1 otnitpulrs COMPUTbgA MAIDDIDA PROCESiIN6i AND CONVbRKlOh4 XQUIPML'NT The Choractron A Wallind-Pierce Iqutpment 1 Aurox Mag netic Wire Storage C CRC Ferro-Resonant Flip-Flop C The Flight Research Laboratory formerly Office of Air Research Automatic C'mputer being built by the General Electric Company Syracuse New York in to be delivered to Wright Field in the spring of 1952 It in a coded decimal single address serial machine using a 10 000 word magnetic drum memory magnetic tape input and output and typewriter input aud printing 17% Wii oimation contained in this issuo was gathered in early December 1951 -1- • •'• • ' r THIS DOCU MNT IS BEST QUALIT-Y AVAILABLE THE COPY UJRNISHED TO DTIC CONTALNED A SIGNFICANT NUMBER OF VC DOT NOT WHr• GES• REPRODUCED FROM BEST AVAILABLE COPY It can fll 1 0101Amlilpil t g DII Ioili nI om 1t11l4 mit hterg 1411111tmIl It 'inkti it0 1hai i I%ki' In the 11141411 11v %4f1 104Me 1114 111y twill Miln I lit lmtalruilltna two aptiondI ac 'urac4 111411111tillt' 11 twil bInt to strmat on taio be por'futmod till both nunt I ttjtltttwll wall tI'lavtlP it11 Alnpl litlly of ina till enamup The 'tt 'tpmter vont a in p po l a i rol litur un o l ish plujln heI lrio11 Inst Illu ma in himlo tuly lt on phtg In wlt wlQ 1 MIfip volaint a till one I $ liont wilhIta tnkib ' i of plsintlviri lirnteln t Reell 1fferent I VIPe 'itf Much In ri to all III the 't etfunmito 1 were kiffli' lont I llIl up'141%I 11 401 lulvill 1110 tti in 1160 11101 4tttp1 01ir'ie ha11111 wt it' Ad huit ll sea It 14ea log nt Isunder wayv The CADAC A now oloct Ion it utma e i -moquene ki'dd4 Itia i 011iU0' put rtAl lod ths VA DAt hasl recently4 Heat's 5 v t pi ma til 1340 W F14 I 11gunito Itoulova it Itaw I honti C alifotrnia tll' the Canthr idge's AlIt 14orvo I 4bOVItraIVIi lit addltti onIIthe uptual arilthmet Ic Insterumul toil add oubtlract julltilliv 16114dIvide Ithii o rikltat h a oottret print iihift totitet andI toot fitr ovortflmmw are Itncluded lto flip dmitt'11 A thirid addret'es vokile in 0mltlitytiui booet s'onllruclit byVfipm 01omputer The0 meionly vonliutAt of at mlaigneivi drum with a vt'upAvlty tfit123 Iiio ntis grouped lit Idl channel lach shier this druml -otatma lat 40 rpa ibm avorIaige thiep -addressi commnand requires abhout one ilottloti 1 40 140c t1'0e ntgt about I o and one -half 2-1 2 turanai Mirin l mpu taot ionl mthte talboo and litld'mes ' a rit holId tit three one wordm rg'jstor till the drum lif 04 woruli In fihe design oftit 1 comupt er Umall stat and mntimtllsaton of the ttumbu'r- of tubl#s wore stressed h 111al1I therm ArO te Akiti 1115 tubes and 2500 crysital diodes i titte computer The word longth In 30 binary digits itumtbea' being txprm'm'ad ats mtagititudes and Mlini lying between I and -1 Input and oultput Art by olvictric typtewritters4 with ituntera being exproilsed in octal form An an outgrowth of the collaborative prtogramt mtowuntder way to produce saeveral modified SMACa reviated dvalgite havte beent deve'loped for the phtysicals form of the basic building elements in the machine A single plug-in pu kage has been desIgued tot aill of the basic tube and diode functions another pat'kagu' for the electrical delay line's antd fintally one for th - specialized delay line terminatibons Almost all oft thu nmachine circuitry will be constructed out of theste three packages The packages have been tested and are' now in hand production Typical circuits are being assembled and proved in onl the present SF AC F'or examnple litternially the lock-out counter of the Williams memory is composed of packages and tin the itux iniry equipment the sanme packages are used in the uutscriber An external selector has been put into regrular operation on the 3EAC by means of which automatic selection may be made fromn among any of in different input-output units The SWAC Since the last report in this Newsletter the accelerating voltage in the cathode ray tubes of the memory system has been lowered with a consequent improvement in flaw conditions but anl accompanied Increase in spillover Under these ci'cumstanIces the stock of cathode ray tubes had to be resorted in order to obtain the best useable tubes Several 3KPi tubes have been delivered and have been put into use with goodi performance with respect to spillover The introduction of the magnetic drum into the computer system is well under way Both a new small single and a new double tube plug-in unit have been designed The initial circuitry on the drum will utilize a pulse frequency of approxinmately 60 to 70 kc which will give a distinct advantage in that it will simplify the circuit design The system as now being constructed will give a maximum memory of about 5000 words with an average transfer time of approximately 500 microseconds per word which is obtained by transferring from the drum to the Williams tube memory a sequence of numbers during one revolution of the drum starting the actual transfer at any arbitrary word and stopping at the end of one revolution -2- Whlrll d I I41la'llN allveathld qualIly bz•twe nl sillli a 441Ihnl 1111%1 itim tirA 1v itI of h1 adaa11 1 Approxliiuatl1i U ialll% ota i'i 111tvi I woI with pa'wiAl Appliatlhat Il Is to nake the military slid 0SIIPn lIl AllpllgAla i p•t TIl' Whirlwind iolpultl' avolialth' foa I the alill thh l'I h lu'iplai hatl1 oto I'broNpar' h workers at MIT and usln any Ianalulliy sot Awitchl Ily i andt in otlip't ai'iie it' lenit o intal lt a11 III1 11i 11hkM It atppil'Arm tah Iha'plala'lIt' wlhtihrt lhim of effievincy to t I'III al IA1r1a1a by tmi l t lone oplarhal use the voitnpulter l1r litollrv iau rIaoil rlltl only tAloew imulvtut ettlotilh limre AVa14il1 abl la that pa'arorliaolr And IIha numblere' tit oaxpatrloiicet' of nIat hinI llnile Tito iomputlrr hals ellr Aivailability Conit AandlplroWiln tit anl equal rate wlli hniml appli'a'lirlla' d hlay lAlltit' nal'a are Aauria ll aliarut In lail lal Prevent plans are It attlolt its mtAkv tho preiparatiloll of pli'tograalis An easily loarned tdlt lve unlr van withorut diflt'ully set up his own program readily performed task soi Ilth a it' rott r'ather tihan require tho mtrviro tif an oxalrioncetd progrannimr An steps in Implementilh this plan a well -catalolgued tll easilyll said library of xubroutailla lis lIrog built up xplanatory text ire being developed- and effective mnthods of having experienced describing methoids oif lrolaarAntllg all personnel provido advive and aisiratainev to the useil' Ara boing worked out A number if people interosted in such diverse problems as digitally -controlled milling machines missile trajectories oil reservoir production ambipolar diffusion and optical constants of thin metal deposits have already mot up succesaful programs of their own Further development of the subroutine library and til forthcoming expansion of the prevent limited 348 registers ktorage capacity will greatly favilitate toach work A seCond baink otitIt storage tubes has beon added to the computer and will soon be available for use This will at least double the storage capacity used up tio the present LM r_9e 'hool Automatic Compui er 48M_ The final design of the basic circuits for the MSAC have been completed Preparation of schematic and layout diagrams was initiated and standardization of circuits and layout techniques was accomplished through the use of technical design memoranda describing the' basic circuits Over 50% of the schematics for the MSAC have been completed Construction of a single unit the Dispatcher Memory Loop is now under way This unit contains most of the typical circuits of the MSAC and will occupy one rack of the machine Tests will be conducted on this rack to determine the final operating char Rcteristics of the circuits before the remainder of the machine is constructed Procurement of components is continuing and fabrication of units such as pulse transformers delay lines and germanium diode clusters is planned in the near future The Burroughs Labo rator y Computer Enhancements have been made in the Burrorighs Laboratory Computer to increase its memory capacity to increase the flexibility and capacity of the teletype input-output system and to incorporate automatic multiplication and division The memory capacity has been increased from 800 nine-decimal-digit words to 5300 ninedecimal-digit words The storage is divided into 10 bands of 500 words per band plus 300 words that are common to all bands The desired band is selected by a programmed instruction Addresses from 100 through 399 are common to all bands but addresses from 400 through 899 re uire that the proper band switch be set up This change required the addition of 90 read-write heads on the druin plus the necessary circuitry The computer was shut down 31 hours and 35 minutes for this enhancement Multiplication is accomplished by repeated addition and division is accomplished by direct subtraction Both operations require an average of 50 milliseconds for their execution This change required two magnetic shift registers and the necessary Pulse Control Equipment used for the control circuits The factors are stored in the shift registers to obviate making reference to the drum during the operations An eighteen-digit product and the quotient plus the remainder are -3- l eri'ltum %if Iht oate i nsanipuhlation and the flexibility it the available followinlg the operitllh i Pulae Control tUnIto oinly 50 hntirni %vurpri' 4wird fit imalt the ehanlf•o The rr-dev•e the followir4 tit the telutypis input-output Mysillln im nearly completed The system will include 3 tranamittor tiletributorn 2 piage printelrs and 2 roporforiatorm Any combination tif the abovo can be programmed to allow better control of the format of the printed page and to aillow the inclusion of an Input word with output worde on a perforated tape The problems solved on the computer Include the following solution of simultaneous equations inversion of matrices ram design parameter calculations of computer circuits simulation of logical vietworks random number generation and sample production control problem The Naval ProvinGOround Calculators The Aiken Relay Calculator Mark I continues to operate six days a week 24 hours a day During the past three months it has been occupied with various items relating to ballistic research as well as the preparation of general ballibtic tables for bombs and rockets Experience with a new epoirlmental checking circuit for automatically checked results has thus far proved to be a valuable asset especially in helping to locate the sources of many machine errors The results of the cormputation have also been more reliable The Mark III Calculator is also being operated six days a week 24 hours a day The relative percent of good running time is under that of Mark Il but significant progress has been made during the last month During this report period the Calculator has been used entirely for the integration of trajectories in connection with the preparation of a general ballistic table Aberdeen Provig Ground Computers The ENIAC A new function table control panel of 4 switch set and 9•3 plug board controlled lines was put in operation with the Eniac in September The new table was designed and constructed by the Computer Research Branch and has performed satisfactorily The new unit increases the program capacity of the Eniac by 30% and since it is plug board controlled it shortens somewhat the set-up time required for changing problems on the machine During the period 1 August through 31 October 1951 the Eniac has completed computations for 27 different problems which involved 56 changes of program dealing with such varied topics as bomb drag studies guided missile flight path trajectories reduction of yaw and swerve data from transonic missile firings gamma ray and neutron transmission through various thickness of matter by Monte Carlo techniques and e firing tables and bombing tables a b c d The ORDVAC The Ordvac has been completed and testing is in progress During the test period the Ordvac has carried out test operations which used all of its orders for periods frequently reaching four to five hours and on one occasion reaching twelve hours without error At present it appears that the -4 - maito read itrotlnd tIt iii ý it IIt' or Ii l twvnty Iiut te•ts ui't' c'on tIinuIitg for tht Pi p 1 41' o1f dotetI mitning this itoli tit ii v' i 'r• tlVY al lld 14' 16ite its inc rease I'VAC EU The' firsrt large vileh probilemi Invovini Vg the dete ril inathc ift the propertvalutof matrices up to the twelfth ordv'r was 4ittisf•c'tort'ly conpleted oil the lEkdwve' Mign ifying that tit nhachint is ready for production A number of testing and compltutitonal r••it ities essentii or the t reatment of large-scale problems are I t'roMently hbeing develolped PIECIAL P URPOSE C OMPUTE p MAD DIn Recent engineering changesi In the MADr IDA digital differential analyzer have produced such radical improvements in the computer's officietncy and mathemnati al flexibility that carlier models are now considered as obsolete Northrop Aircraft Is recalling M l MADDIDA- previous to Serial No 6 and bringing them up to date The most significant advancement has been the installation of a test panel for marginal checkIng which enables the operator to examine quickly the operating margin of all parts of the computer Operating experience has shown that through the use of this check panel virtually trouble-free operation can be obtained On a recent test run of MADDIDA No 9 covering a period of 300 operating hours scheduled and emergency maintenance totalled less than 2% of total time A argenumber of circuitry changes have been made to increase the margin if reliability of the computer and several new features have been added Among these are a time reversal switch which permits the computer to halt and back up in the middle of a problem an overflow alarm which automatically halts the computer and notifies the operator if a variable starts to exceed its expected range and on the latest machines a logical change which permits the codrwr to multiply any variable by a constant without increasing the number of integrators used In the line of auxiliary equipment a drum type digital graph plotter has been developed recently by the Engineering Research Company of Los Angeles Thorough testing has shown this plotter to be well engineered and extremely reliable Northrop Aircraft has recalled all early models of the decimal tabulating equipment for MADDIDA due to the fact that they were difficult to maintain in operating condition A new model decimal tabulating output device is now under test and is expected to be in production within 30 days A new MADDIDA installation has recently been completed for the Air Force 3151st Electronics Group at the University of Utah According to present schedules six more MADDIDA installations will be made in the next few months DATA PROCESSING AND CONVERSION EQUTTOP ENT The Charactron The Charactron is a special-purpose cathode-ray tube developed by engineers of Consolidated Vultee Aircraft Corporation Los Angeles California A matrix containing character-shaped openings is located between the electron gun and the fluorescent screen A stream of electrons directed through the matrix openings results in a shaped beam that provides a presentation of characters on the screen of the tube where they can be read or photographed An electrostatic deflection system is utilized for character selection iti the matrix and either electrostatic or electromagnetic deflection is used for positioning character images on the screen Thus the proper sequence of applied deflection voltages selects and positions matrix characters so that input signals are translated into visual intelligence Among the more general appiications of the 'haractron are 1 data conversion and tabulation read-out 3 high-s peod printing 4 high -speed if analoguo or digital Info r mat lol 2 computeh com mun Icat ons and 5 monitoring and mesý age display equ 1pm en One possible type of data converter Is on that will meastire physical quantit i in the form of electrical potential 4 and present them as three-place numerals on the Charaction screen In such i device thi voltage levels can be con'veited to decimal number values within a few milliseconds and with an accuracy of onle part in one thousand Another possible type of converter will be used In rhis equipment referred to as a combination with high-speed printers •f codled lnfo•martniion Charactrontype Printer will have printing rates ranging fronm 1000 to 10 000 characters per second thus satisfying the needs of voluminous p'iotlog at high speeds Printing can b- donL oil ordinary paper using a dry photographic protcess Wal lind - Plerce Equipment Thc' Wa Hind Piere Corporation 109 Bornd Street Redondo Beach California which was formed in January 1951 is now completinig W01k on two L•h- A 1 fro- the Naval Electronics Laboratory San Diego California In the course of this work the followingr pieces of equipment are being developed 1 A digital-to-analogue translator having an accuracy oi 1% Sixteen serial ten-place binary nurabers are translated into 16 output voltages having a range from 50 volts to -50 vwlts 2 An analogue-to-digital translator which converts the angular outputs of 16 shafts to 16 ten-place binary numbers and transmits this information serially in less than one second 3 A digital pick-off which senses shaft rotations to less than 10% ten binary places with negligible load on the shaft being sensed Sampling rate is 50 times a second Aurex_ Magnatic Wire Sto raie Some years ago the Aurex Corporation 1117 N Franklin Street Chicago Illinois developed a new magnetic wire recording device after which special prototypes were developed and built under an Office of Naval Research contract It is essentially a cartridge containing two opposite cavities in which the wire may be coiled naturally on the inside of one and drawn from the center of either cavity to the other by means of a revolving shaft and a controlled pinch roller unit which is positioned between the cavities when the cartridge is mounted on the unit The cartridge may be made in different forms to accommodate a small amount or up to many thousand feet of wire The smallest cartridge need be not over one and one-half 1-1 2 inches in diameter The wire has been run without any difficulty whatever up to 27 feet per second and can be run faster Recording experiments indizate considerably greater efficiency than is now obtainable with wire Since the cartridge is stationary and only a few inches of wire are in motion inertia is no problem and the starting and stopping of the wire is practically instantaneous CRC Ferro -Resonant Flip_-Flop The CRC Ferro-Resonant Flip-Flop which utilizes the principle of ferro-resonance to produce bi-stability in a simple series LC circuit has been placed on the market by the Computer Research Corporation With the establishment of the basic flip-flop design laboratory work is now going forward on packaging and embodiment in counting and other devices A decade ring counter has been constructed which employs no tubes or diodes and functions up to 20 kcs The counting unit proper exclusive of neon read-out occupies a space l x 2 x 3 Actually it is feasible to combine the flip-flops in rings of twenty or more elements Thus it also becomes possible to divide incoming pulse rates by any integer between two and twenty Furthe development has been in the direction of increased speeds and the most recent flip-flop Model MC functions at the rate of 100 kcs -6- nu wiF F 1