Chapter 4 – 1959 to 1969

From Mainframe to Minicomputer

Russian Sputnik Satellite 1957

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State of Computing – 1960’snote: driving forces – pg. 110

Great Demand for Computing IRS: Mainframe + Punch Cards JFK: 1961 Moon Challenge Great economic growth &

prosperity New computers – the MINI Technology already obsolete

2

IBM

1960 70% Market Share stability

Research Labs (US, Europe)-slow payoff Could control market, releases (usually) Philco – transistor production Others need to find area unserved by

IBM

3

Government Influence

Dept. of Defense - needed computer technology

Researchers began defining work

Demand for computing was heavy Govt. had funding – to lots of places

See how this influenced the development

4

IBM 7000

Massachusetts Blue Cross

1960 - IBM 7070; 1401 for I/O 6 months- transferred 2,500,000 records

from cards to tape (150 file cabinets) AUTOCODER (not FORTRAN or COBOL) 1965 Medicare established

Won job of administering for Mass. Fall 1966 - fully computerized - 1st state Also rented another 7070 (drove cards

daily) 1969 - 3 IBM System /360’s + COBOL, 24-7

5

NASA- Ames Research Center

Mountain View, California, 1940 Soviet Sputnik 1957 & JFK Moon

Challenge Became part of NASA in 1958

Honeywell H-800 for wind tunnel - real time + others for dedicated purposes DEC, Scientific Data Systems, EAI, IBM

Demands on central computer grew 100% per year in 1960’s

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NASA-Ames Research Center (cont.)

Direct Couple System - 1963 7094, 7040 (I/O), 7740 (Remote

Terminals) Replaced in 1968 with System 360 model

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1969- System/360 model 67 For time-sharing, not a success 1971 –connection to new ARPANet

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NASA-Ames Research Center (cont.)

Timesharing not a success Design problems Incompatible work patterns No longer “real time” for wind

tunnel Table 4.1 p. 118 – computers at

Ames8

IRS- Internal Revenue Service

During WWII – need $ Taxpayers from 8 to 60

million Withholding

Punch Card – 1948 IBM 650 - 1955

Kansas City regional center

1.1 million returns – test

1959 - authorized to computerize fully IBM won bid 1401 @ each

regional center 7070 national

center Still 400 million

cards a year Changeover complete by

1967: cards to magnetic drum

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IRS (continued)

No NW – flew tapes/cards around TAS - Tax Administration System

Late 1960’s – implement new ideas $650- $800 million Distributing computing to 10 centers Direct access via 8,000 terminals Network Lot of work in to security plans

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Honeywell H200

TAS (continued) 1974 - Nixon resignation / IRS records Public questioned security 1977- Computerworld – GAO report

“Proposed IRS system may pose threat to privacy”

Congress held hearings – IRS no trusted Jan. 1978 - IRS dropped TAS 1985 - IRS system collapsed, bad press

Congress approved change

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Put a Man on the Moon

Batch would just not work Needed lots of money for real-time Mercury Monitor (system software)

Data could interrupt processor to note life- threatening situations

Trap processor: checked levels of priority; saved contents of registers

Evolved to real-time version of System/ 360 O.S. a significant advance in system software

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Minicomputer

New, Not a competitor to mainframe

Driven by technology Factors defining Mini

Architecture Packaging Third parties Price Financing

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Architecture of Mini

Short Word Implications

Small addresses, values, instructions

Instructions more complex Instruction “modes” With new transistors, processor still simple inexpensive and fast

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First Mini at CDC 1957 - CDC (Jack Norris) developed

1604 Seymour Cray – CDC 160

1960 – CDC Model 1604 Designed model 160 for I/O

Word = 12 bits 8,000 word memory Fast clock

160A sold for $60,000 (stand alone) 1963- Jack Scanllin, Scanllin Electronics

2-160A’s to provide online stock quotes to brokers 15

Digital Equipment Corp (DEC)

Founded 1957; K. Olsen, H. Anderson Olsen: MIT Whirlwind;

MIT’s TX-0 (transistors) 1957-Most advanced in world

1959 - PDP-1 designer Ben Gurley Designed to take full advantage of

transistors (not a “re-fit”) 100,000 adds/sec; 4,000-6,000 8-bit words

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PDP- 1 features

Transistors DMA: defined mini architecture

No I/O channels (with own memory) Fast, little effect on 1717processor Cheap and simple

Interrupts: up to 16 levels circuits to handle in order

1 IBM channel cost more than PDP-1: $120K Sold about 50, only moderate success

financially, but very innovative. 17

DEC’s Policies

Customer Relations Contrast to IBM Sold Computers Encouraged customer modifications

Had sophisticated customers Necessary - small company

Manuals “A Sears- Roebuck catalog” for DEC

products Sold cheap or gave away 18

PDP-8 -1965 Sold 50,000;

plus single–chip versions 12-bit word Germanium transistors - faster Indirect addressing; Paged memory; innovations DECtape – portable, r/w both directions, like disk Price??? $18,000; down to $10,000

Very low; shocked industry Model 33 ASR - Teletype Corp.

Used ASCII, ctrl & esc Keys (Photo Pg. 134)

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PDP-8 (cont’d)

Term: Minicomputer Tendency toward assembly language OEM – original equipment mfg.

Added specialized equipment Early use LS-8 (by Electronics Diversified)

Contained a PDP-8A Controlled lights for A Chorus Line

PDP-8 on a potato picker (P. 136)

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DEC Culture

The Mill, Maynard, Mass. 1965- $15 mil. Revenues 1970 - $135 mil.

Proud of differences – IBM Eventually competed with IBM -

VAX Read P. 136-139

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Chapter 4 – 1959 to 1969

From Mainframe to Minicomputer

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