Chapter 5 - MSU Computer Science
Chapter 5
1961-1975
The “Go-Go”
Years &
System/360
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
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
IBM 360 - 1964
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”
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
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
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
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.
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
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
THE Time-Sharing Problem
Page 155
Lots of wasted cycles between key strokes
– instructions
No efficient method for program swapping & keeping track
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
Time-sharing
IBM Stretch
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 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
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
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
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
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
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
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.
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?
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
Chapter 5 – 1961-1975
