1. Chapter 5 1961-1975 The “Go-Go” Years & System/360

2. IBM & The Others  1963- $1.2 billion (70%)  1965- $ 3 billion  1970- $ 7 billion  Sperry – Rand (UNIVAC)- mid 1960’s - $ 145 million  CDC (mini), Honeywell, Philco, RCA, GE, Burroughs, NCR- mainframe builders  Snow White & 7 Dwarfs  1970’s BUNCH  Stable until 1980’s personal computers

3. System/ 360  Announced April 1964 - “full-circle” of customers – business & scientific  Line, 6 models-sw upward compatible 25:1 performance range Plus 150 different items  Fortune Magazine: “You bet your company”  1100 orders in 1 st month In 5 months, 2200 orders  Success was a “threat ” Could not meet demand

4. IBM 360 - 1964

5. SPREAD - IBM committee  Met daily 2 months in 1961  Review past & decide the future Couldn’t continue to “upgrade”  Needed a “unified product line”  “Scalability” Fred Brooks, Gene Amdahl  “can’t be done”

6. Scalability  1951- Maurice Wilkes, Manchester University  “best way to build an automatic calculating machine” was to build its control section as a little stored – program computer of its own  “Micro- programmer”; microcode  Page 148

7. Scalability – Adopted for 360  Allowed common instruction set Specialization & optimization for models Via microprogramming  Read only memory  Compatibility with earlier IBM’s Emulation  Separated design process from control logic

8. Compatibility  Microprogramming facilitated  Emulated earlier IBM models 7070 and 1401 Up to ½ of 360 time was emulating  Due to new HW, new machines “emulated” old ones up to 10 times faster  Honeywell H-2000 + liberator emulated 1401 – sold well!  Software - more permanent than hardware  1401 programs run today Part of Y2K problem

9. 360 Features  16 General purpose registers  32-bit words Finally a power of 2!!  8-bit character code – byte (1956) EBCDIC – true 8 character code Originally also included ASCII; dropped  Channels retained  Peripherals  PDP-8: real-time, labs, etc.

10. Side Note on ASCII  1963- American National Standards Institute Adopted 7 bit ASC II, not 8 8 holes across paper tape would weaken it too much Became established in mini’s

11. Time-sharing & 360  System/360=> 360 degrees=> “full circle of customers” Did not address time-sharing No dynamic addressing  @ this time – interactive=> one user  Batch jobs “shared” time – one job in memory  John McCarthy- MIT Each user has illusion that complete machine & SW at her disposal

12. THE Time-Sharing Problem  Page 155  Lots of wasted cycles between key strokes – instructions  No efficient method for program swapping & keeping track

13. Time Sharing - Mid-1960’s  MIT, IBM 7090 CTSS - Compatible time sharing system Supported just a few users  Defense Dept.- Project MAC Chose G.E. over 360 GE became leader in time-sharing  IBM crisis Problems with program swapping Had not thought it would be important Model 67: TSS failure  Anti-trust lawsuit – premature announcement

14. Time-sharing  Progress was made – but still slow to develop workable time-sharing -- Demonstrated feasibility but not practicality  Much turmoil in industry GE sold to Honeywell Movement to PDP machines - UNIX IBM threatened by success IBM Stretch

15. IBM System /3  IBM 360 could not compete in mini market  System /3 Incompatible with 360 $1000 month Small 96 column punch card Eventually floppy disk

16. The 1960’s  Leasing companies IBM too expensive  Development costs  Others 20% less  Could withhold technology  1970 - IBM 370 360 compat. w/ time-share, integrated circuits (cpu,mm)  1978 - IBM 4300 360 compat, low cost  1978 – AS/400  Leasing companies in debt due to upgrades  “Go-GO” years  Stocks soared for all electronics companies

17. Compatible Mainframes  Possible attacks on 360 line Information to numerous companies  1964 - CDC 6600 (above) Designer Seymour Cray Supercomputer – Fastest performance  Small sales ~ but impressive ~ serious customers Sued IBM – announcement 360 model 91

18. Compatible Mainframes  1964 – RCA – Spectra 70 Series Ran 360 Software (1 st clone) 40% less $ than IBM, 4 models Used true integrated circuits Lost in 1970 ~ 370 announced (IC’s) Out of computer business  Another round of buy-outs

19. Plug Compatible Manufacturers (PCM) Others targeted 1 part ~IBM system Tape drive, memory, CPU These companies soared IBM  price cuts, packaging  1969-75, 10+ lawsuits Gene Amdahl-1970  Left IBM, own co.  Fujitsu, other Japan

20. Software Houses  Industry needed SW!!!  Companies providing software Automatic Data Processing (ADP)~payroll Computer Sciences Corp. (CSC) American Management Systems  IBM Included programming, service in price 1968 agreed to separate (lawsuit) For 360 success  need for others to provide SW & service  Bad IBM SW – OS 360, PL/1

21. Software Houses – cont’d  1962 - EDS – H. Ross Perot Left IBM over “leasing of time” Success with government contracts Based in Dallas  Ramo-Wooldridge  TRW Manufacturing + SW + Service Military, space, etc. Later into business apps.

22. IBM vs. Justice Department  Filed January 1969  Lasted 12 years  Sell computers, Unbundle  Dropped January 1982  PC Effect  ? Why didn’t IBM pursue PC market?

23. The “BUNCH”  Unisys = Burroughs + Univac (86)  AT&T hostile take-over of NCR (91)  Honeywell Partnered with NEC, Bull & Olivetti Phased out of computing  CDC – up & down – suffered Cray departure PLATO (p. 175)  Education system failure  Ahead of it’s time

24. Chapter 5 – 1961-1975 The “Go-Go” Years & System/360