CS 185C/286: The History of Computing November 28 Class Meeting Department of Computer Science San Jose State University Fall 2011 Instructor: Ron Mak

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 2 Dan Greiner  History of Computing Speaker Wednesday, Nov. 30, 6:00-7:00 PM Auditorium ENGR 189 Reception before the talk in ENGR 294 at 5:00 PM  “Legacy of the IBM System/360 Architecture” IBM “bet the company” on this architecture in the early 1960s Is it still relevant today after nearly 50 years?

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 3 Research Project Reports  Due Monday, Dec. 12 (first day of finals week) What you’ve posted to the IEEE Global History Network Any attachments (software, etc.)  Report grading Quality of your research  What were your primary and secondary resources?  Whom did you interview? What questions did you ask?  How well did you solicit and respond to criticism and advice? Quality of your final deliverable  Final grade 33% attendance + essays 67% project

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 4 SAGE Computer System  An intercontinental air-defense network commissioned by the U.S. military “Semi-Automatic Ground Environment” Started in the 1950s and operational by 1963 Operational until 1983 Total cost: $8-12 billion in 1964  Designed to coordinate radar stations Detect atomic bomb-carrying Soviet bombers and guide American missiles to intercept and destroy them Linked by long-distance telephone to radar defense sites  large-scale wide-area computer network 23 “direction centers” each with a SAGE computer that could track as many as 400 airplanes  concrete-hardened bunkers across the US and Canada

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 5 SAGE Computer System

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 6 SAGE Computer System  Designed by Jay Forrester and George Valley Professors at the MIT Lincoln Laboratory Forrester (1918- ) also developed core memory  Largest and most expensive computer system 250 tons 60,000 vacuum tubes 13,000 transistors > 150 CRT monitors each with a light gun ~3 MW of power 800 programmers Built by IBM

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 7 SAGE Computer System Specifications  Architecture duplex CPU, no interrupts, 4 index registers 32-bit words 75K instructions/second  Memory 4 banks of 64K words, 6 us cycle time 150K words magnetic drum 4 tape drives, ~100K words each  I/O keyboard CRT with light gun teletype with 1300 bps modem

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 8 The IBM 7030 Stretch  World’s fastest computer from The CDC 6400 was faster starting in 1964  IBM’s first transistorized supercomputer “A giant step” that “stretched” existing computer technology Hardware-supported parallelism  First one delivered to Los Alamos National Laboratory  Considered an embarrassing failure by IBM _

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 9 The IBM 7030 Stretch

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 10 The IBM 7030 Stretch

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 11 Business Context  In April 1955, the UC Radiation Laboratory at Livermore processed bids to build a high-performance 2 MHz decimal computer system called the Livermore Research Computer (LARC) for $2.5M IBM proposed a machine that would be 4 to 5 times faster but for $3.5M to be delivered in 42 months Univac won the bid with a proposal to deliver in 29 months  In September 1955, IBM proposed to deliver a supercomputer to the Los Alamos National Laboratory Worried that Los Alamos would also order a LARC Binary computer with “speed at least 100 times” that of the IBM 704 IBM won the proposal in November 1956  $4.3M contract with delivery in 1960

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 12 IBM 704  First mass-produced computer with floating- point hardware  Introduced in systems sold from 1955 to 1960  Core memory One 38-bit accumulator One 36-bit quotient register Three 15-bit index registers FORTRAN and Lisp were developed on a 704

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 13 Famous IBM 7030 Stretch Developers  Project manager: Stephen Dunwell, Had 180 people by 1957  Hardware designer: Gene Amdahl Left IBM when passed over by Dunwell (rehired in 1960)  Fred Brooks Later led the IBM System/360  John Backus Inventor of FORTRAN Backus-Naur Form (BNF)  John Cocke and Harwood Kolsky Wrote a simulator for the Stretch architecture Cocke later became “the father of RISC architecture” Kolsky is now a UC Santa Cruz emeritus professor

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 14 Stephen Dunwell Stephen Dunwell (left) and Erich Bloch (right)

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 15 IBM 7030 Stretch Customers Machine name BuiltCustomerDelivery X-1PoughkeepsieLos Alamos Scientific Lab (LASL)1961 K-1KingstonLivermore Radiation Lab (LRL) [now LLNL]1961 K-2Kingston Atomic Weapons Research Establishment (AWRE), Aldermaston, UK 1962 K-3KingstonUS Weather Bureau [now NWS]1962 K-4KingstonNaval Weapons Lab (Dahlgren)1962 K-5KingstonMITRE Corporation1962 K-6Kingston Commissariat a l'Energie Atomique (CEA), France (Harvest) PoughkeepsieNational Security Agency (NSA)1962 A ninth Stretch was built and kept by IBM.

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 16 IBM 7030 Stretch Features  8-bit byte  Instruction pipelining and prefetch (lookahead) Start slower memory operand fetches early and overlap them with the operation of the fast floating-point arithmetic unit  Memory interleaving Up to 6 banks of memory  Error correcting memory One-bit errors automatically corrected Two-bit errors (unlikely) caused the running program to be interrupted temporarily for a memory refetch

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 17 IBM 7030 Stretch Features  Multiprogramming One running program can interrupt another program running at a lower priority Memory protection  Rich instruction set Decimal or binary operation Radix conversion Floating point Indexing Variable-length operands  Standard Modular System (SMS) cards

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 18 Failure...  Despite all the architectural innovations, the Stretch was not 100 times as fast as the IBM 704 Benchmarks showed that it was only 30 times faster  Major embarrassment to IBM Only 9 systems were built Originally priced at $13.5M, reduced to $7.8M  Stephen Dunwell was made the scapegoat and demoted to a staff position

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 19 Postmortem Analysis  System performance was overhyped in the beginning  Overly complex design Features were added without proper cost-benefit analyses  System simulations were started late Kolsky reported that the simulation results were “generally disregarded” anyway  Series of transistor budget cuts Reductions in the number of transistors  Transistors were only half the predicted speeds Memory accesses, particularly the registers, were slower  Early arithmetic operation timings were over-optimistic

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 20 Postmortem  “The fact that the overall performance has dropped by only a factor of 3 in view of these difficulties is greatly to the credit of the engineers.” [Kolsky] _

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak 21 IBM 7030 “Stretch” Legacy  Most of the core architectural features of the IBM System/360 were pioneered by the Stretch  Features such as instruction pipelining and prefetch, and memory interleaving are used today in the IBM PowerPC _

Department of Computer Science Fall 2011: November 28 CS 185C/286: History of Computing © R. Mak and Redemption  IBM CEO Tom Watson Jr. eventually recognized the important contributions of the Stretch  At IBM’s Annual Awards Dinner in March 1966, Stephen Dunwell was named an IBM Fellow _