EDVAC Ryan Kidder Calculator of the Future
Quotable Quotes • Where a calculator on the ENIAC is equipped with 18,000 vacuum tubes and weighs 30 tons, computers in the future may have only 1,000 vacuum tubes and weigh only 1 ½ tons. - Popular Mechanics, 1949 • Never trust a computer you can't lift. - Stan Mazor, 1970 • If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get one million miles to the gallon, and explode once a year, killing everyone inside. - Robert X. Cringely
The Birth of EDVAC • Engineering design of ENIAC frozen • Ballistic Research Lab at Aberdeen, MD elects Moore School of Electrical Engineering, University of Pennsylvania • Dr. von Neumann’s “First Draft of a Report on the EDVAC”
Dr. von Neumann’s Report • Proposed “a very high-speed automatic digital computing system, and in particular with its logical control” • Automatic computing system defined as “a device which can carry out instructions to perform calculations of a considerable order of complexity” • Five distinctions of device
Dr. von Neumann’s Report • Device should contain specialized organs for elementary arithmetic • Logical control of device can be best carried out by central organ • A device which carries out complicated operation sequences must have sufficient memory capacity • Must have device to transfer information from outside recording medium to central control and memory • Must have device to transfer information from central control and memory to outside recording medium
The Birth of EDVAC • Contract signed on April 12th, 1946 between the Ordinance Department and the Trustees of the University of Pennsylvania • To design and develop a preliminary model of a small Electronic Discrete Variable Automatic Calculator • Originally allotted $100,000 ($962,000 today) • Final cost $467,000 ($4.5 Million today)
Design • EDVAC I – Automatic addition, subtraction, multiplication, programmed division, no internal checking. Memory of 1,000 words. • EDVAC II – Fixed decimal point, basic arithmetic processes automatic, added automatic checking. Memory of 1,000 words. • EDVAC III – Automatic floating decimal point, same features as EDVAC II, memory of 4,000 words. • Decided on EDVAC 1.5
Features • Binary system of numeration • Serial arithmetic mode • Four-address command structure • Duplicate circuitry for check purposes • Major improvement over ENIAC, which required considerable human effort to change programs, EDVAC uses magnetic wires
Organization • Reader-recorder – contains equipment required to transfer information from the heads to the processing delay and vice versa • Control – contains all operating buttons, lamps, control switches. Sends orders to the dispatcher to start the machine; may also send words to high-speed memory • Dispatcher – decode orders received from control and memory, emit control signals to other units
Organization • High-Speed Memory – used for temporary storage of operands during arithmetic operations; contain apparatus to decode addresses received from dispatcher and select memory position whose contents are to be transferred out of memory or to be replaced by incoming data • Computer – performs rational operations on pairs of numbers; answers compared with arithmetic unit • Timer – emits clock pulses at intervals of 1 microsecond and timing pulses at intervals of 48 microseconds
Finished Product • Delivered to Computing Proving Ground in August, 1949 • Problems with marginal circuits solved within 18 months, started operation in late 1951 • Averaged 15-20 hours per week of solving mathematical problems by 1952 • 145 hours by 1961
Later Improvements 1953 - IBM card input-output adapter unit 1954 - Magnetic drum for an additional 4,608 words of medium-speed storage 1958 – Built-in floating point arithmetic unit 1960 – Magnetic tape system for additional storage
Uses at Ballistic Research Lab • Exterior ballistics problems such as high altitude, solar and lunar trajectories, computation for the preparation of firing tables, and guidance control data for Ordnance weapons, including free-flight and guided missiles. • Interior ballistics problems, including projectile, propellant and launcher behavior, e.g., physical characteristics of solid propellants, equilibrium composition and thermodynamic properties of rocket propellants, computation of detonation waves for reflected shock waves, vibration of gun barrels and the flow of fluids in porous media. • Terminal ballistics problems, including nuclear, fragmentation, and penetration effects in such areas as explosion kinetics, shaped charge behavior, ignition, and heat transfer. • Ballistic measurement problems, including photogrammetric, ionospheric, and damping of satellite spin calculations, reduction of satellite doppler tracking data, and computation of satellite orbital elements. • Weapon systems evaluation problems, including antiaircraft and antimissile evaluation, war game problems, linear programming for solution of Army logistical problems, probabilities of mine detonations, and lethal area and kill probabilities of mine detonations, and lethal area and kill probability studies of missiles.
EDVAC Statistics • Addition – 864 microseconds • Subtraction – 864 microseconds • Compare – 696 microseconds • Multiply – 2,928 microseconds • Floating point add – 960 microseconds • Floating point multiply – 1,248 microseconds
EDVAC
