Reminescences of Early Days
of Computing in Ireland
Gordon Clarke M.A., CEng., F.B.C.S., C.I.T.P., F.I.C.S.
Hollerth
H
ll th (BTM) HEC 1201
Computer
y
Accuracy !!!
y
I ask in advance that others with experience of
that time excuse any minor inaccuracies
y
I am relying to a large extent on my own
recollections and some illustrations from the
I t
Internet
t
E & OE !!!
y
Historical Context – Early Inventions
The early IT Industry
Business Systems Environment in 1940s
and 50s in Ireland
L d up to
Lead
t the
th first
fi t Computers
C
t
The first Computer System in Ireland
y
Some events of the following 10-15 years
y
y
y
y
Scope of presentation
y
y
Printing Press
The Jacquard Loom (1801)
y
◦ Early Use of Machine Readable Data
Later uses of Punched Cards included controlling
Music – e.g.
e g Fairground Organs
y
Babbage’s Analytical Engine – mid 1800s
◦ Ideas and Design like a modern computer
◦ Difficult to implement with Mechanical
Technology
gy – Though
g proven
p
OK in 1991
◦ Ida Lady Lovelace– 1st programmer
Historical Context - Early
I
Inventions
ti
y
y
y
y
y
y
Data content exceeded previous Census
Analysis by existing methods not practical
Job put to Tender
Tender won by Dr Herman Hollerith –
T b l ti
Tabulating
Machine
M hi
Company
C
1896
Patents acquired later by “The ComputingT b l i
Tabulating
Recording
R
di
C
Company””
This later (1924) became
“International Business Machines”
The US Census of 1890 – Impetus
t Invention
to
I
ti
Hollerith Tabulator & Sort Box 1890
Card Reader on Census Tabulator
y
y
y
y
y
y
Early European Interest
1910 Census won by Powers Machine Co.
Developments in Punched Card Systems
The war and advances in Electronics
Leading
d
to the
h first
f
computers
The Early years of Commercial Use of
Computers
Developments 1900
1900--1950
y
y
y
y
c1905 Everard Green from the UK visited
the US
He saw the application of Dr Hollerith
Hollerith’s
s
new inventions in Freight Accounting on
the Railways
These were effected through the
recording of data by means of holes
punched in cards – quaint language
H wrote
He
t about
b t thi
this in
i letters
l tt
to
t a
Financier, Sir Rayleigh Philpotts
P i t l published
Privately
bli h d memoirs
i off EG
European Interest
y
y
y
y
y
y
y
Finance arranged.
arranged
Formation of the British Tabulating
Machine Company.
Company
1907 Agreement between this company
and “The Tabulating Machine Company”
Covered the “Sterling Area”
H d
Hardware
d
developed
l
d ffor £sd
£ d
Everard Green became the first CEO of
the BTM Company.
UK BTM #1 Factory established in a large
shed at Letchworth Herts.
The British Tabulating
g Machine
Company
y
y
y
y
y
y
y
Mrs Metcalfe sister of Everard Greene
married to a Capt. Metcalf
One of first women graduates of LSE ?
Founded Calculating & Statistical Services
HO iin D
Dublin
bli with
ith branch
b
h in
i Belfast.
B lf t
Offered a Comptometer Service to
i d
industry
Obtained the Hollerith Agency for all
Ireland (incl. N.I.)
Later included a Punched Card Bureau
Service
Links to Ireland – C&SS
y
Full Keyboard £sd
£sd Comptometer
y
y
y
y
y
y
Dublin Office at #15 Harcourt Street
Founded a Punched Card Service Bureau
using BTM equipment
Sales and Maintenance - by local staff
BTM Manager,
M
System
S t
Design
D i
and
d
Technical Support provided by staff
seconded
d d ffrom th
the UK
Myself and Michael McMahon were the
fi
first
llocall staff
ff employed
l
d to replace
l
these
h
Alan Exley sold the first Computer to
CSET
Calculating & Statistical Services
y
y
y
y
y
y
Use of Hollerith & Powers Inventions in
Business became widespread
Training was done by the manufacturer
The level of sophistication of the
equipment increased considerably
Flexibility in use of the equipment
provided
id d b
by ““plugboards”
l b
d ” – limited
li it d
“programming”
M h i l Speeds
Mechanical
S
d increased
i
d substantially
b
i ll
BTM developed its own products, but still
sold many of the IBM products.
Developments in Punched Card
Systems
y
Provided by the Manufacturer
Training – Moor Hall, Cookham
y
Bradenham Manor
Computer Training
y
y
y
y
y
y
y
y
40 Column Cards
Entirely mechanical sensing
Bowden Cables
Factory produced “Custom” Boxes.
Incredible
d bl mechanical
h
l engineering
Entered the computer market with ECC
and PCC
Merged with BTM in 1959 to form ..
International Computers and Tabulators
((ICT))
Powers--Samas
Powers
y
y
y
y
The Card Stopped at Position “d”
d
Pins “c” dropped if there was a hole
Allowen pin “b”
b to rotate into vertical position
Pressure above “a” transmitted to “e” effected
action where there was a hole (vv?)
a
b
c
d
e
Powers Card 40 Columns x 12
y
Top was the size of the 40 Column Card
with 480 Holes
y
Bottom slightly
l h l llarger controlling
ll
Print
Positions, Addition and Control Breaks
Box was about 15cm high.
Typically 480 Bowden Cables
running from top to bottom of Box
Crossing in a maze!
Powers--Samas Control Box
Powers
y
y
y
y
y
y
Made to a very high standard specification
Supplied only by IBM or BTM
Very Significant Revenue Source
Custom Design for each Installation
Filed in Standard Boxes of 2,000 Cards
Some installations would have hundreds
of thousands or even many millions of
Cards
Punched Cards
y
y
y
y
y
y
y
Hollerith originally used Round Holes.
Holes
Later changed to rectangular Slotted
Gave better Contact At High Speed
Punch Die covered 1 Column -12 holes
Milled
ll d 1 Verticall C
Column
l
at ffront and
d 12
2
cross milled at back
Verification by different operator –
Machine indication if data did not agree
with Punched Data
Powers used Round Holes with 2nd hole
offset making oval for verification
Punching
g & Verification
y
y
y
y
y
y
Only other Media at the time
Main application - messaging
Not relevant in most cases
Could not be sorted
Provided
d d cheaper
h
alternative
l
ffor input to
some computer systems of very small
d
data
volumes
l
Probably the largest use in Ireland was in
the ALT Message Switching Centre
Punched Paper tape
y
y
y
y
Ledger Cards
Paper Documents
Microfilm for Archiving
Photocopying
h
Wet Only
El
Electrostatic
i came much
h llater
Other Media
Hand Punch c1923
IBM Auto feed Card Punch c 1960
Sorter
y
Depending on when the brush made
contact with the drum, the magnet would
direct the card to a different pocket
Brush Sensor
Magnet
C d width
Card
idth
Hollerith Sorter
Card Row
Collator
Tabulator – c1932
y
y
y
Read-out from the brushes of the two
card stations sent to contra windings on
Magnetic clutch
Control Change – stopped Card feed
Started End of Group Functions
Card
Direction of
Cards
Next
Card
Tabulator Cycle and group control
IBM Tabulator c 1940
Type 588 ? 900 Series Tabulator
& Summary Punch
y
Solely mechanical
y
Impact to Cast Type Face
y
Carbon
C
b
S
Sets – very expensive
later NCR
y
1970s Dot Matrix Impact printers
◦ Electrostatic Copying
Printing
y
y
y
y
Sorters – racks
Collators
Tabulators
S
Summary
Punches
h
y
Card Storage
Interpreters
p
- Bull
y
Later Electronic Calculators / Computers
y
Typical Punched Card Machine
Room
y
y
y
y
y
y
y
y
y
y
y
Early - Maxwell
Maxwell, Faraday
Faraday, Hertz,
Hertz
Edison - Marconi
1905 Thermionic Valve – Sir Ambrose Fleming
g
1908 Triode – Amplification - Lee de Forest(Yale)
1918 Electronic Flip-Flop –Eccles / Jordan
(Electronic Data Storage)
Pulse Techniques – Radar & Bletchley Park
Use in First Electronic Computers
1946 ENIAC
1947 Bell
B ll Labs
L b – Transistor
T
i t
1949 EDSAC– 1st Stored Program (Cambs)
Leo 1 based on EDSAC
1951 UNIVAC 1st commercially available
Development of Electronics
Sir
Si A
Ambrose
b
Fl
Fleming
i
– in
i 1936
Leo 1 – General View
Leo 1 – view
i
towards
d Console
l
y
y
y
y
y
y
Dominated by BTM
Powers-Samas – Substantial (Vickers)
Punched Card Systems had progressed
during 1st half century
Early Electronic Computing
WW ll Bletchley Park – Colossus
Fi t St
First
Stored
d Program
P
Computer
C
t
1st Generation
Mergers with
Powers –Samas, GEC, Ferranti
English Electric – Then Fujitsu
UK Situation
i
i
y
Cambridge – EDSAC & Leo
y
Manchester – Ferranti
y
Birkbeck
kb k College
C ll
– BTM
Hec 1200 Prototype 1953
Universities in the UK
EDSAC
y
y
y
y
y
First applications were mathematical
Used Mercury Delay Lines as Memory
World’s first Computer Service Bureau
was based on Leo.
W
Won
contract
t
t for
f Army
A
Payroll
P
ll
Quality Control was critical in all early
systems, b
but particularly
i l l so with
i h MDL.
MDL
EDSAC & Leo
Ferranti - ATLAS
About 6 of these were installed
y
y
y
y
y
Hollerith Customers in Ireland included
ESB, Bord na Mona, Aer Lingus, CSET,
parts of CIE
50-100 Installations
ESB Installation was one of the largest
Tabulator installations by BTM / ICT
O l D
Only
Data
t Storage
St
media
di -Punched
P
h d Paper
P
Tape and Punched Cards (80 Column
H ll ith and
Hollerith
d 40 C
Column
l
P
P-S)
S)
Electronic communications - Telex and the
T l h
Telephone
At time of CSET installation
Hec 555 Programmable Calculator
Plugged Program n Hec 555
Picture of Hec 1201
HEC 1201 O
Outline
tli
S
Specification
ifi ti
HEC 1202
y
y
y
y
y
y
y
Input 80 Column Hollerith Punched Cards
Output 100? lpm line printer 100 pps (based
on type 588 ? 900 SeriesTabulator)
Output 100? Cpm Card Punch
Memory solely 4 x 40 bit registers
Program and data storage on Drum
64 tracks each with 16 x 40 bit words
Speed 1 ms cycle per word (add 2 x 40 bit
registers)
Data sorting and collating performed off-line
Hec 1201 Computer System
y
y
y
y
y
y
y
y
y
Payment to Farmers for Beet Deliveries at
4 factories
Carlow Mallow,
Carlow,
Mallow Thurles and Tuam
Campaign from late Oct – early Dec
S b t ti l C
Substantial
Computation
t ti
required
i d
Delayed Payments to Farmers – only
fi li d after
finalised
f
Ch
Christmas
i
Objective....
Automate system as far as practicable
Speed
p
up
p Payments
y
to Farmers
Save Temporary Clerical Staff
Sugar Company Problem
y
y
y
y
y
y
Saving of large number of Temporary
Clerical Staff
Immeasurable value in good will
As it turns out it was worth quite a bit !!
C
Computer
t ~ £33,000
£33 000
Salary of a Clerical operative at the time
c£300
£300 p.a.
Widely Publicised
Decision to install Computer
y
y
y
y
y
The Hundreds of Temporary Clerical Staff
had not been employed
Computer delivery was delayed
Farmers were not being paid
Wh
When
delivered
d li
d two
t
off the
th English
E li h Staff
St ff
(Norman Frances & Alec Willies) had to
oversee the
th operation
ti
till th
the end
d off the
th
campaign.
The actual Computer Room was a former
Seed Store !
Installed in 1957 – Late !
y
y
y
y
y
First Manager Mr.
Mr McDowell became ill and
died
Erratic Electricity Supply
Difficulty in operating of the system
System settled down well
Permanent Maintenance staff
In addition to the Late Delivery
y
Weigh Truck or Rail wagon on Entry
Take Sample
Weigh Sample
Wash Sample
Weigh
h Washed
h d Sample
S
l
Put part of weighed sample in solution in
Polarimeter and take reading of Sugar%
Offload Beet to processing
Weigh empty Truck
y
Price = f(Sugar%)
y
y
y
y
y
y
y
Beet Delivery
y
y
y
y
Compute Price and apply to create Beet
Delivery - Credit Value
Compute Freight Charge – Debit Value
Compute Freight Subsidy - Credit Value
C
Compute
t BGA Levy
L
– Debit
D bit Value
V l
Beet Delivery Computations
y
y
y
y
Computer & Equipment Room
Data Preparation
Control and Reconciliation
Error Checking
Data Processing Department
y
y
y
y
y
y
Data Preparation Department
Rows of Operators at Card Punch or Card
Verifying Machines
Punch the data into Cards
V if –by
Verify
b re-entering
t i
d
data
t
Use different machine and operator
Manually check discrepancies
Data Preparation
Master / Balance / Cheque Card
y
Clerical update data from Weighbridge
and Laboratory
Update Beet
Delivery
Docket
Delivery
Dockets
Punch Beet
Delivery
Data
Beet
Controls
PreStatement
System
B t Deliveries
Beet
D li
i
Beet
Deliveries
y
Prepare other transactions
Seeds,
Sacks,
Fertiliser,
Loans,
Interest,
Molasses etc
Other
T
Transaction
i
Documents
PreStatement
System
Other Transactions
Other
Controls
Prepare
Trans. Data
Other
Transactions
y
.
Changes
Farmer
Master Data
Collator
Prepare Changes
Changes
Sort to Account
and Type
Sorted
Changes
Updated
Master
Maintain Master Data
Replaced
Old
Unmatched
Changes
y
Outline
Farmer
Master
Data
b/f
Balances
Beet
Deliveries
Other
Transctns
Sort to Account – Date - Transaction Type
Collator
Unmatched
Master Data
Unmatched
Transactions
Merged
Mast / Trans
Statement
System
Prepare Data for Statement
System
y
Outline
Merged
Mast / Trans
Hec 1201
Statement
Program
Farmers
Statements
& Controls
c/f Balance &
Cheque Cards
Beet and other
Controls
Clerical Check
Controls and
Discrepancies
Farmers
Cheques &
Controls
Hec 1201
Cheque
Program
Statement & Cheque System
y
Reconstitute Master Files and “File”
File Others
Merged
M
d
Mast / Trans
Unmatched
U
t h d
Master Data
c/f Balance &
Cheque Cards
Collator
Complete
Master
Processed
Transactions
to File
Post Statement Run
b/f Balance
Cards
Statement & Area Totals
System Design Tools !
y
y
y
y
y
y
y
Allocate each instruction to Drum Address
Update Drum Chart
Code the Next Instruction Address
Take Account of Drum latency
and
d IInstruction
t
ti
“Fetch”
“F t h” time
ti
Only Memory 4 x 40 Bit Registers
Had to Shift data around or
Store Temporarily on Drum
Programming
i
Considerations
id
i
y
y
y
y
y
y
y
No Divide Function – Use Sub Routine
No P Register – Had to set Exit before
entry to s/r
Had to convert input from BCD & Imperial
Units to Binary
Imperial measures were used at the time
£ d and
£-s-d
d Tons-cwt-qrs
T
Had to Convert for output back to BCD &
Imperial Units
Space Required for lists of Constants 1,
10, 100, 1000 etc
Programming
i
Considerations
id
i
y
y
y
y
y
y
Program read and Stored on Drum
To start program, One entered the
Address of First Instruction
Could Single Shot through Program on
Colsole
Current Instruction was Displayed
C
Contents
off all
ll Four
F
Registers
R i
were
displayed
When proven, Program could be summary
punched in Binary at 12 Instructions per
card
Program Testing
y
y
y
y
Only a single stream of data could be read
Could code other variables into a Data
Section of the Program
Could read in a small set of Data before
main data and store it
Worst practice – but I often saw it
U off Literal
Use
Lit
l Values
V l
Small “Files”!
y
y
y
y
y
y
y
Data on Punhed Cards - Costly to Manage,
Manage to
Control & to Store
There was no easy back
back-up
up
Only Came in 80 Character Chunks
Often used 2 additional rows at top of card
for minor data – e.g. Sign, Type Qualification
etc
Year was packed into either 1 or 2 Digits –
Hence the Y2K Problem
Month could use the imperial pence coding
With
t tthe
e older
o de systems,
syste s, there
t e e was
as the
t e
problem of negative complements
O h Considerations
Other
id
i
y
If an Error Ocurred...
Ocurred
y
On a Valve Machine –
One had to consider the possibility that
the Computer was wrong!!
y
Not as bad
N
b d as the
h Leo
L
type storage !
Mercury Delay Lines
Reliability
588 Control Panel Layout
Output
O t t Punch
P
h & Zero
Z
C
Control
t l
Page 1 – Weekly Statements
Page 2 - Weekly Statements
Some Embedded Constants
Drum Chart
y
The only other 1200 series installations in
Ireland were
y
The N.I. Ministry of Finance
ICL Factory
F t
in
i Castlereagh
C tl
h in
i Belfast-1202
B lf t 1202
y
y
One of these was installed in the Dublin
Service Bureau
y
English
g
Electric DEUCE in Short &
Harlands
Northern Ireland
y
y
y
y
y
Accounts
Payroll
Tynagh Mines
PERT
Management Game
G
H
Hec
1201 ?1202 later
l t
1301 in
i
Bureau in Adelaide Road
1966 Administrator with Winning
Team
y
y
y
y
y
y
y
y
y
British Tabulating Machine Company
Powers-Samas
GEC
Ferranti
English
l h Electric
l
Elliot
Leo Computers
E.M.I.
Marconi
U.K. Computer suppliers in 1959
y
y
y
y
y
y
y
y
II.B.M.
BM
Univac
RCA
R.C.A.
Honeywell
N.C.R
C
Burroughs
G.E.
?
U.S.
U
S C
Computer
t
Suppliers
S
li
att that
th t
time (IBM and the 7 dwarfs)
y
y
y
Very Expensive when they arrived first
with 2nd Generation
Typically only 4 Drives
- Automated the Sort Processes
- Moved the Merge Functions into the
application programs
y
Speeded up Processes
y
Allowed for Fast Machine Back-up of Data
Magnetic Tape Files
y
y
y
y
y
y
1st Targets were the large Organisations
These were mostly Hollerith Customers
First major loss was the ESB
Installed the first IBM Computer –IBM650
L t A
Later
Aer Lingus
Li
IBM 1620 – Scientific / FORTRAN / P. Tape
T C D And
T.C.D.
A d Gateau
G
Cakes
C k
Elliot 803? Agricultural Institute (AnFT)
I.B.M. Arrival
y
ICL supplied two systems in competition
with this
◦ ICT 1301 – from GEC Stable
ICT 1500 (from RCA – not sold in Ireland)
y
IBM sold a number of these....
these
◦ Gouldings Fertilisers
◦ ESB (1410 an enhanced model)
y
IBM also had tabulator installations with
◦ Albright & Wilson
◦ Waterford Glass
IBM 1401
y
y
y
y
y
y
y
y
Second Generation Systems included....
included
Sugar Company
P J Carroll
P.J.Carroll
Esso Ireland
Jacobs
b Biscuit Factory
Clondalkin Paper Mills
The Revenue Commissioners
Sunbeam Wolsley
y
ICT 1300 Series Installations
y
One of the major applications in this Co.
Co
Biscuits were sold in “Square” Tins
y
Automating Manufacturing Processes at
the time
Jacobs – Van Loading
1301 Operator Display
1301 Function Chart
Core Memory
TAS Assembler Sample
y
y
y
IBM 360 Series - Byte
ICT 1900 Series – 4x6Char 24bit word
Wide ranges
Target Market
◦
◦
◦
◦
y
Larger Tabulator
L
T b l t Installations
I t ll ti
Other Organisations with large Databases
Banks
Government & Local Government
Programming Language
◦ COBOL
PL1 (IBM)
RPG
Third Generation – Integrated
g
Circuitry
y
Allowed direct access to data
y
Very Expensive initially
y
Approx: £10,000
£ 0 000 for
f 5-10mb
0 b
Arrival of Disk Storage
y
y
y
y
y
y
y
Up to about 1970 – Still using Ledger
Machines
Mainly from NCR and Burroughs
Auto Line find – Punched at side of Card
A t Pick-up
Auto
Pi k
off Balance
B l
– Magnetic
M
ti St
Strip
i
Magnetic Ink Encoding Standards
Cheque Sorting
Led to Customised Lodgement and
Cheque
q
Books
Banks
y
In the early 1970s
y
AIB went to IBM
y
BoI went to ICL
C
Banks were a key Market
y
y
Targeting the remainder of the old
Tabulator market
IBM System 3
◦ Upgrade to Tabulator Installations
◦ Used RPG – program to emulate the basic
tabulator functions.
ICT followed using the lower part of the 1900
Range
g
Success of IBM System 3
ICT 1900 Installation
y
y
y
y
Mid 1960s Bunker Ramo Inventory
System
Torn Tape Message Switching
Airlines like the Banks had prepared the
way for inter company business
communications
1969 IPARS System
S t
◦ On-line reservations System
◦ Linked
Li k d tto th
the SITA Message
M
Level
L
l System
S t
y
Automated Message Switching
Aer Lingus
y
Irish Computer Bureau Services (ICBS)
c1966 – Ex ICT – bought Honeywell
y
Aer Lingus Systems Services
L t Cara
Later
C
Data
D t Processing
P
i
y
y
System Dynamics – Software &
Consultancy
y
Clondalkin
Independant
I d
d t Computer
C
t
Service
S
i
Bureau Services
ICT Management in 1965
Key to Photograph 1965
y
y
y
y
y
y
y
y
Simon Lavington (E1) Elliott 152 1950
Elliott Nicholas
1952
Elliott 153 (DF computer)
1954
Elliott/GCHQ OEDIPUS (311) 1954
David Pentecost ((E2)) Elliott/NRDC
/
401 1953
Elliott 402 1955
Elliott 403 (WREDAC) 1956
Elliott 405 1956
Fujitsu Page 1
y
y
y
y
y
y
y
Simon Lavington (E3) Elliott 802 1958
Elliott 803 1959
Elliott ARCH 1000, etc. 1962
Simon Lavington (E4) Elliott 503 1963
Elliott 502 1964
Terry Froggatt (E5) Elliott 900 series 1963
Richard Overill (E6) Elliott 4100 series
1966
Fujitsu Page 2
y
y
y
y
y
y
y
y
Simon Lavington (F1) Ferranti Mark I
1951
Ferranti Mark I Star
1953
John Gosling (F2)
Ferranti Mercury 1957
Chris Burton (F3)
Ferranti Pegasus 1956
Ferranti Perseus 1959
Ferranti Sirius
1961
Frank Taylor (F4)
Ferranti Orion 1 & 2
1963
John Buckle (F5)
Ferranti Atlas 1 & 2
1962
Fujitsu Page 3
y
y
y
y
Peter Niblett (F6)
Ferranti Apollo
Ferranti Poseidon
1962?
Ferranti Argus series
1963?
Ferranti Hermes ????
y
y
y
y
Tba (Leo L1 – L3)
LEO I 1951
LEO II
1957
LEO III
1962
Fujitsu Page 4
1961
y
y
y
y
TBA (EE N1
N1- N4)
English Electric DEUCE
1955
English
g
Electric KDN2,, KDF7,, KDF6 1962
English Electric KDP10 1962
English Electric KDF9 1963
y
y
y
y
y
Roger Johnson (T1)
BTM 1200 series
Martin Wright (T2)
1961
ICT 558 FCC
Fujitsu Page 5
BTM HEC 1953
1956
ICT 1300 series (GEC)
1962
y
y
y
N/A – US Design (T3) ICT 1500 (RCA 301)
1963?
N/A
/ – US Design
g (T4)
( ) ICT 1600 (RCA
(
3301)) ?
Virgilio Pasquali (T5) ICT 1900 series 1964
Fujitsu Page 6
The first computers used vacuum tubes for circuitry and
magnetic
ti drums
d
for
f memory, and
d were often
ft
enormous,
taking up entire rooms. They were very expensive to
operate and in addition to using a great deal of electricity,
generated a lot of heat, which was often the cause of
malfunctions.
y First g
generation
a o computers
o pu
relied
d on
o machine
a
language,
a guag ,
the lowest-level programming language understood by
computers, to perform operations, and they could only
solve one problem at a time.
time Input was based on punched
cards and paper tape, and output was displayed on
printouts.
y The
Th UNIVAC and
d ENIAC computers
t
are examples
l off fi
firstt
generation computing devices. The UNIVAC was the first
commercial computer delivered to a business client, the
U.S. Census Bureau in 1951.
y
First Generation - 19401940-1956:
V
Vacuum
Tubes
T b
y
y
y
Transistors replaced
p
vacuum tubes and ushered in the second g
generation
of computers. The transistor was invented in 1947 but did not see
widespread use in computers until the late 50s. The transistor was far
superior to the vacuum tube, allowing computers to become smaller,
faster cheaper,
faster,
cheaper more energy-efficient
energy efficient and more reliable than their firstfirst
generation predecessors. Though the transistor still generated a great
deal of heat that subjected the computer to damage, it was a vast
improvement over the vacuum tube. Second-generation
g
computers still
relied on punched cards for input and printouts for output.
Second-generation computers moved from cryptic binary machine
language to symbolic, or assembly, languages, which allowed
programmers tto specify
if iinstructions
t
ti
iin words.
d High-level
Hi h l
l programming
i
languages were also being developed at this time, such as early versions
of COBOL and FORTRAN. These were also the first computers that stored
their instructions in their memory,
y, which moved from a magnetic
g
drum to
magnetic core technology.
The first computers of this generation were developed for the atomic
energy industry.
Second Generation
The development of the integrated circuit was the hallmark
of the third generation of computers. Transistors were
miniaturized and placed on silicon chips, called
semiconductors which drastically increased the speed and
semiconductors,
efficiency of computers.
y Instead of punched cards and printouts, users interacted
with
ith thi
third
d generation
ti
computers
t
th
through
hk
keyboards
b
d and
d
monitors and interfaced with an operating system, which
allowed the device to run many different applications at
one time with a central program that monitored the
memory. Computers for the first time became accessible to
a mass audience because they
y were smaller and cheaper
p
than their predecessors.
y
Third Generation
The microprocessor
p
brought
g the fourth g
generation of computers,
p
,
as thousands of integrated circuits were built onto a single silicon
chip. What in the first generation filled an entire room could now
fit in the p
palm of the hand. The Intel 4004 chip,
p developed
p
in
1971, located all the components of the computer - from the
central processing unit and memory to input/output controls - on
a single chip.
y In 1981 IBM introduced its first computer for the home user, and
in 1984 Apple introduced the Macintosh. Microprocessors also
moved out of the realm of desktop computers and into many
areas of life as more and more everyday products began to use
microprocessors.
y As these small computers became more powerful, they could be
linked together to form networks, which eventually led to the
development of the Internet. Fourth generation computers also
saw the development of GUIs, the mouse and handheld devices.
y
Fourth Generation
HEC 1201 O
Outline
tli
S
Specification
ifi ti