History of Electronic Computers

History ECE 795 History of Electronic Computers 1642–1945 Mechanical Era 1946– Electronic Age: divided into 4/5 generations History of Electronic Computers 1 History ECE 795 History Electromechanical Z1, Z3 Konrad Zues (Germany) 1938−1941 G. Stibitz Bell Labs (USA) 1937−1943 Mark I, II Howard Aiken IBM (USA) 1939−1944 EDSAC M.V. Wilkes (England) 1946−1949 EDVAC J. von Neumann 1946−1950 ENIAC J.P. Eckert & J.W. Mauchly 1946 Electronic Cryptanalytic Machines (not much info, classified) −special purpose, plugboards & switches −COLOSSUS (1943) allied code−breaker ACE A. Turing 1946−1947 History of Electronic Computers 2 History ECE 795 Electromechanical Zuse: worked independently of England and U.S. • Z3 (1941): first operational, program controlled, computer – pgm control: tape, 8 bits/command – arithmetic unit: binary, floating point, word length 22-bits (sign, 7-bit exponent, 14-bit mantissa), builtin operations: +, -, ×, ÷, square root, times (2, .5, 10, 0.1, -1) – store: 64 words – output: lamp display w/ 4 decimal places and decimal point Electromechanical 3 History ECE 795 • Z3 destroyed in 1944 air raid • believed to have independently developed ideas of: – – – – binary arithmetic — Liebniz program control — Babbage instruction formats — Ludgate floating point representation — Torres • lacked idea of conditional branch Electromechanical 4 History ECE 795 H. Aiken (Grace Hopper) • Mark I (1940–1944) 1. Decimal Arithmetic 2. punched paper tape for program control 3. 2-address instructions • Mark II (1944–1947) 1. floating point numbers 2. multiple arithmetic units, usable simultaneously H. Aiken (Grace Hopper) 5 History ECE 795 Stibitz • Complex Computer (1938–1940) 1. complex numbers: +, -, ×, ÷ 2. binary arithmetic 3. automatic decimal/binary conversions • Relay Interpreter (1939–1943) 1. BCD number representation 2. Error detecting codes Stibitz 6 History ECE 795 Electronic Computers: Instantiation John Atanasoff (1939): applied mathematician, Iowa State Univ • developed special purpose machine to solve “large” systems of linear equations • claims to be first with operational electronic computer, largely unrecognized J.P. Eckert and J. Mauchly • Moore School of Electrical Engineering, Univ of Pennsylvania • ENIAC (1945) – first general purpose computer – not stored program Electronic Computers: Instantiation 7 History ECE 795 ENIAC 1. Vacuum tube technology (18,000) 2. decimal computer 3. 20 word memory (A1, A2, ..., A20) called accumulators 4. word size, 10-digits 5. programmed by manual switches/plugboards ENIAC 8 History ECE 795 EDVAC (1945–1951) first stored program computer design, conceived because ENIAC: • difficult to program • limited memory capacity • slow memory access first draft report of EDVAC written by John von Neumann in 1945; therefore he is credited w/ developing stored program concept. EDVAC (1945–1951) 9 History ECE 795 Moore School Lectures (summer 1946) EDVAC Moore School Lectures EDVAC (1951) (built by others at Moore School) IAS (1952) J. von Neumann Inst. for Advanced Study EDSAC (1949) M.V. Wilkes Cambridge U. Eckert & Mauchly BINAC (1950) UNIVAC (1951) (taken over by Sperry Rand Co. for several years was undisputed leader of U.S. computer market) Moore School Lectures (summer 1946) 10 History ECE 795 First Generation (1946–1954) Technology: vacuum tubes, acoustic/CRT memories Hardware/Arch: centralized control, fixed point arithmetic Software: assembly languages Examples: • EDSAC (1949) Cambridge U. – memory hierarchy (primary memory to drum) – floating point emulators provided as system routines • ISA (1952) Princeton – CRT memory allowing entire word access as one operation First Generation (1946–1954) 11 History ECE 795 • Whirlwind I (1951) MIT – ferrite core memory • UNIVAC I (1951) – magnetic tapes w/ ability to read fwd/bkwd, and w/ buffering and error checking capabilities. – because of slow mercury delay line memory was rapidly replaced w/ ferrite core based UNIVAC II (1957) – first successful computer – Grace Hopper: Mathematic → Algol, Flowmatic → COBOL • IBM 701 (1953) – disk and tape secondary memories • MADM (?) Manchester U. – index registers First Generation (1946–1954) 12 History ECE 795 • IBM 704 (1955) – hardwired floating point arithmetic (first) – indirect addressing (first) Memory sizes in this era will still quite limited. Therefore, some machines were constructed with drum memories (e.g., IBM 650 (1954)). Because of slow access, the assembly operations were place at strategic points on drum — at first by hand, later by programs (e.g., SOAP). First Generation (1946–1954) 13 History ECE 795 Second Generation (1955–1964) Occurred primarily due to technological advances (transistor). Technology: discrete transistor, ferrite core memories, magnetic drums Hardware/Arch: floating point arith, index registers, I/O processors Software: High Level Languages (FORTRAN, COBOL, ALGOL, LISP), system software (e.g., compilers, subroutines libraries, batch monitors) Examples: • UNIVAC 1103 (1956) – floating point hardware – program interrupts (first) Second Generation (1955–1964) 14 History ECE 795 • IBM 709 (1959) – hundreds sold at several million dollars each • IBM 1401 (1961) – 20,000 sold • Honeywell H-800 (?) – replaced 1401 w/ movement to S/360 • IBM 7094 (?) – data channels Second Generation (1955–1964) 15 History ECE 795 • EDSAC II (?) – micro-programming (first) • CDC 6600 (1964) – multi-functional units • Burroughs B-5000 (1963) – designed to efficiently support Algol-60 (first lang directed arch) • Atlas (1962) Manchester U. – virtual memory (first) Second Generation (1955–1964) 16 History ECE 795 • IBM Stretch (1961) – – – – attempted to push state-of-the-art to the limit instr. lookahead and partial execution interleaved memory hardware support for protecting multiprogrammed tasks • Burroughs D-825 (1962) – first multiprocessor – 2 processors connected to 16 memories (crossbar) Second Generation (1955–1964) 17 History ECE 795 This generation also sees the introduction and widespread use of HLLs (high level languages): FORTRAN (54–57) ALGOL (58–62) introduction of BNF COBOL (59–60) DOD enforced as standard LISP (60–65) MIT Second Generation (1955–1964) 18 History ECE 795 Third Generation (1965–1975) Caused primarily by: 1. development of SSI and MSI integrated circuits, 2. generalized use of micro-programming to implement instruction sets, and 3. the generalization of multiprogrammed operating systems. Third Generation (1965–1975) 19 History ECE 795 Technology: integrated circuits (SSI, MSI), semiconductor memories Hardware/Arch: micro-programming, pipelining, multiprogramming, multiprocessing Software: timesharing, virtual memory, O/S Examples • CTSS (early 1960’s) MIT – time sharing • IBM S/360 (1965) – architecture family – micro-programming Third Generation (1965–1975) 20 History ECE 795 • MU 5 (?) – pipelining • ILLIAC IV – array processing (4 quadrants of 64 processors; only 1 quadrant built) Third Generation (1965–1975) 21 History ECE 795 Notes for 3rd Generation multiprogramming: overlapped execution of different pgms w/ 1 CPU timesharing: multiprogramming system that allows for many interactive users multiprocessing: machines that provide for concurrent execution of programs by multiple CPUs SSI ∼ 10 gates/chip MSI ∼ 10-100 gates/chip LSI ≤ 10,000 gates/chip Third Generation (1965–1975) 22 History ECE 795 Fourth Generation Technology: LSI, VLSI, bit-slice logic Hardware/Arch: large scale multiprocessors, multicomputers, language directed architectures (including RISCs), distributed system architectures (including LANs), fault tolerant processors Software: distributed operating systems, advanced compiler optimization techniques, electronic mail networks, concurrent HLLs Examples: • SYMBOL (1971) Fairchild – HLL directed architecture (SPL) – migration of virtually all s/w (including compiler) into h/w – only one built Fourth Generation 23 History ECE 795 • C.mmp (1977) CMU – multiprocessor (16 PDP-11’s connected by crossbar to 16MM) • Cm* (1979) CMU – multicomputer (interconnected clusters of processors; each processor has own memory; hierarchical communication structure) • Intel iAPX 432 (1980) – 2 VLSI chips with 160,000 transistors – load balancing – object oriented arch Fourth Generation 24 History ECE 795 • HP 3000 (?) – stack machine • Burroughs B1700 (?) – multiple-language directed architecture (COBOL, RPG, FORTRAN, Basic, and SDL) – bit addressable memory (length specified); variable size ALU – dynamically swappable micro-program – on low end machines, micro-program resides in MM • RISC I, II (1982, 1983) Berkley • MIPS (1982) Stanford • IBM 801 (1982) Fourth Generation 25 History ECE 795 Further Readings • Randell, B. (ed), The Origins of Digital Computers, 1975. • Shurkin, J. Engines of the Mind, 1985. • Wilkes, M.V. Automatic Digital Calculators, 1956. • Annals of the History of Computers. • Rosen, S., “Electronic Computers: A Historical Survey,” ACM Computer Surveys, Vol 1, No 1, 7–36, March 1969. Further Readings 26