DIGITAL COMPUTER SIV- T 7-1I M'TV t'Y' L B1 1 f 1TlrInrT OFFICE OF NAVAL RESEARC0 7- w ots -- yorl s digital c #qqx vlfq • MATHEMATICAL SCIENCES DIVISION Vol 2 No 3 1 August 1950 KAVEXOS-P-614 TABLE OF CONTENTS 1 2 3 The Aberdeen Proving Ground Computers The Institute for Advanced Study Computer SEAC Formerly calledoNBS Interim Computer 4 5 6 7 8 Institute for Numerical Analysis Computer SW AC Project Whirlwind MADD PA Raytheon Computers The EDSAC Cambridge University England % ' 6 1 TEN ABERDEEN PROVING GROUND COMPUTERS The ZNIAC has recently been used to solve very extensive problems involving three variables Despite the complexity and the novelty of these programs a technical operating efficiency of 80% andan over-all operating efficiency of 55% are being maintained The University of Illinois is now ingaged in the construction of the final Williams tube memory system and the control for the arithmetic organ of the Ordvac THE INSTITUTE FOR ADVANCED STUDY COMPUTER The fabrication of the memory organ for the Institute for Advanced Study computer is completed and tests of this assembly are nearing completion Life tests of 10 and 20 tubes were satisfactorily made and attention is now centering around similar tests for the complete 40 tube unit The results of these tests will be reported on in the next Newsletter Designs have been completed for the remaining components of the arithmetic organ and the control The construction of these units is progressing and will be reported upon in more detail in the next Newsletter SEAC Formerly called NBS Interim Computer On 20 June 1950 the National Bureau of Standards Eastern Automatic Computer called SEAC was formally dedicated as an operating and productive computer Prior to its dedication SEAC had solved several mathematical exercises which were tried out for the purpose of testing thie machine such as the determination of prime numbers the computation of sine-cosine tables and the solution of diophantine equations and also had solved several significaiii robtems such as calculations of heat flow in a chemically reactive material and an initial linear programming problem for Project SCOOP for the Office of the Air Comptroller Department of the Air Force Uby Ol 'lfc C L LA R I t tb H 0U 5E-1 1k hmidI SW'ngfidd 22151distribt'ti Thin documnent has been approved for public rolnclG a2¶d ealo I'M j unimi t - At present the machine is being used both to solve scientific problems and to evaluate the effectiveness and reliability of computer components General engineering tests are being run and work is in progress on several scientific problems such as the calculation of the exponential integral El Z and the Jacobi elliptic functions and a check of the 'neutron capture theory of the relatHwa ah w4aft a ¢ # h • 01 r • -- i 1117 rar i iiia uj p i iw - fice of the Air Comptroller The machine an at preosnt operating has pwuched paper Lape input typewriter output and a 5iZword acoustic memory The magnetic input-output and electrostatic memory are nearing completion INSTITUTE FOR NUMERICAL ANALYSIS COMPUTER SWAC The fabrication of all the units of the computer has been completed and all chassis have been individually checked and operated satisfactorily Checking and testing of the computer as a whole is being done at present and simple routines making use of the entire system have been run on the machine The magnetic drum constructed by the University of California at Berkeley under the direction of Professor Paul Morton has been delivered The design and construction of the chassis needed to integrate the drum into the computer system is now underway Plans have been made to dedicate this computer now officially named the National Bureau of Standards Western Automatic Computer in August 1950 PROJECT WUIRLWIND The first bank of 16 electrostatic storage tubes was connected into the computer at the end of June The rest of the computer including the arithmetic element central control and test storage had been in satisfactory operation for some months Early tests using electrostatic storage were gratifying Problems which had previously been run with the 32 registers of test storage were repeatedwith electrostatic storage Error-free operation for over an hour was obtained using some groups of the available 256 registers others were not as reliable qeliability will be improved during nu and August Sixteen spare storage tubes are on hand Recording and reading have been performed with the Eastman film units but operation is not yet sufficiently reliable to permit permanent Integration with the computer Punched paper tape will be available in August as an interim input-output medium Work on control of magnetic tape will start during the summer An expanded program of courses in Automatic Computation and Numerical Analysis will be offered by the M I T Electrical Engineering Department in 1950-51 Information on prerequisites and admission to the graduate school can he found in the M I T 1950-51 catalog The fall term includes Numerical Analysis and a Seminar in Numerical Analysis by Professor Kopal Introduction to Digital Computer Coding and Logic by Mr Welchman and Control Systems Employing Two-Valued Elements by Mr A E Ritchie of Bell Telephone Laboratories The spring term includes Hunerical Analysis and Laboratory in Numerical Analysis by Professor Kopal Machine Computation by Professor Caldwell and Electronic Computation Laboratory by Mr Verzuh MADDIDA Northrop Aircraft Inc is now in the proceas of building a new model of the MADDIDA having the capacity cf a 44 integrator differential analyzer and a 29 binary digit accuracy The computer will be filled by use of binary keys and information read out visually in the octal number system on a standard oscilloscope A 12-channel input for arbitrary functions and a 12-channel output are also being provided It is expected that the 'otal number of vacuum tubes will be less than 100 The first of these computers will be delivered in about two months and additional copies can be made in about 4 months -2- RAYTHEON COMPUTERS Central control memory external memory and hunting circuits have progressed to the stage where they will soon be undergoing system tests Design of other major components is continuing Tape handling mechanisms are noo in production and are scheduled for completion at a rate af approximately one per week starting in August Magnetic recording head production has been increased to approximately five heads per day THE EDSAC Cambridge University England In order to simplify the preparation of programs forthe EDSAC and to reduce errors in programming a large library of subroutines has been built up These are incorporated into the program of a complicated problem by modifying some of the orders according to their location in the main program at Lthe time the routines are taken into the machine Some of the problems of scientific interest solved were concerned with the following topics Tabulation of the function 1 r x iy x - - 50 01 50 y - 0 01 1 00 oscillation of a pendulum in a submarine gravity survey ray tracing in electron lens solution of a istential equation by the Liebmann process serial correlation group and phase velocity of electromagnetic waves in the ionosphere a matrix problem connected with the wave theory of a molecule and solution of a differential equation arising in the theory d the constitution of a star Comments letters to the editor and additional contributions for inclusion in the Newsletter should be addressed to Code 434 Office of Naval Research Navy Department Washington D C -3- 4