The PascalineBlaise Pascal invented the first digital calculator to help his father with
his work collecting taxes. The user would dial the numbers he wanted to
add together and the machine would automatically add them. The result
would be shown through six small windows at the top of the machine.
The Leibniz WheelGottfried Wilhelm Von Leibniz took the Pascaline one step
further and invented a similar machine to add, subtract,
multiply and divide. The Stepped Reckoner, as Leibniz
called his machine, used a special type of gear called a
Stepped Drum or Leibniz Wheel, which was a cylinder with
nine bar-shaped teeth of incrementing length running
parallel to the cylinder’s axis. The drum is rotated using a
crank. This movement is then translated by the device into
multiplication or division depending on which direction the
stepped drum is rotated.
The Jacquard LoomPunched cards guided Jacquard's Loom in making complex woven
patterns of flowers and leaves into a large cloth. Similarly, Babbage's
Analytic Engine would use punch cards to program data "input" into the
machine, automating the mechanical steps of calculating numbers,
resulting in an "output" on a printed printed page.
The Analytical EngineBabbage worked on his Analytical
Engine from around 1830 until he died,
but sadly it was never completed. It is
often said that Babbage was a hundred
years ahead of his time and that the
technology of the day was inadequate
for the task. The organization of the
Analytical Engine is virtually identical
to that of modern computers having an
input section, a central processor that
performs arithmetic and logical
operations, a memory unit to store
information, and an output section to
make the results available to the user.
Herman HollerithHerman Hollerith combined the
old technology of punched
cards (used in the Jacquard
Loom) with the, then, new
electrical technology of vacuum
tubes, to produce a sorting and
tabulating machine. In this
machine, wires poked through
the holes in the punched cards
then into cups of Mercury,
which completed an electrical
circuit and registered the data
on the card. The 1880 census
took over 7 years to complete.
With the help of this machine,
the 1890 census was completed
in six weeks.
IBMIn addition to solving the census problem, Hollerith's machines proved
themselves to be extremely useful for a wide variety of statistical
applications, and some of the techniques they used were to be
significant in the development of the digital computer. In 1896 Hollerith
founded the Tabulating Machine Company, forerunner of Computer
Tabulating Recording Company (CTR). He served as a consulting
engineer with CTR until retiring in 1921. In 1924 CTR changed its name to
IBM - the International Business Machines Corporation.
The Enigma Machine
As Nazi Germany made war on Europe, its generals and
admirals had a secret weapon. It wasn't a bomb or a gun; it
was a code machine. The Enigma machine was one of
thousands deployed by the Nazis so they could send and
receive encoded messages. The wooden box contained
dials and wheels that could be set with the day's code
instructions. Then, anything transmitted would be in code.
In today's computer world, many of us use
encryption technology to keep our data safe
from others. But in the 1930's, encryption was a
life-or-death matter.
But while the war raged on, British
intelligence officers were capturing the
encoded transmissions and building a
computer called Colossus to decipher them.
They eventually cracked Enigma's secrets
and helped turned the war's tide.
Betchley Park and ColossusBletchley Park was Britain's best kept secret 50 years ago. But
without Bletchley Park, World War II would probably have
lasted another two years. It was at Bletchley that code-breakers
monitored and read the top secret communications between
members of the German High Command during the Second
World War. It was at Bletchley that Colossus was built. This was
Britain's first - and, if the historians at Bletchley are to be
believed, the world's first - electronic computer.
Americans claim to have been
first with ENIAC, but experts
insist that Colossus beat this by
two years. The reason it isn't in
most of the history books is
because it was a secret.
the hut used by the enigma team
ENIACElectronic Numerical Integrator And Calculator
The ENIAC was a large-
scale, general purpose
digital electronic computer.
Built out of some 17,468
electronic vacuum tubes,
instead of switches and
relays, ENIAC was in its
time the largest single
electronic apparatus in the
world.
ENIAC was a secret World War II military project to speed
up the tedious mathematical calculations needed to
produce artillery firing tables for the Army.
UNIVACUniversal Automatic Calculator
The Universal Automatic Computer or UNIVAC was a computer milestone
achieved by Dr. J. Presper Eckert and Dr. John W. Mauchly, the team which
invented the ENIAC computer. In 1946, Eckert and Mauchly were contracted by
the United States Census Bureau to build a computer to help with the increase
in population. They were given $300,000 to build the machine. In 1951, the
machine was finally built at a final cost of over one million dollars.
UNIVAC was the world's first electronic general purpose data processing
computer.
The IBM 650The IBM 650 was the first computer to be mass produced.
The 650 only used about 500 vacuum tubes in its central
processing unit, and was therefore much smaller and more
dependable than the UNIVAC. Because IBM developed a
marketing strategy that discounted rentals of the machine to
universities, the 650 became the computer around which the
new academic discipline of computer science evolved.
In 1957a company called Digital Equipment Corporation (DEC)
was formed. Their original objective was to grab a slice of IBM's
business market and sell million-dollar mainframes. Financial
realities prevailed, however, and a new plan emerged--build a
slightly scaled down computer and sell it for $125,000 to scientific
and engineering markets. DEC computers proved successful
even in other markets, and by 1969--during the era of miniskirts
and miniseries--these computers were universally referred to as
"minicomputers.“ Digital Equipment Corporation merged with
Compaq in 1998. Today's minicomputer vendors include IBM, Digital/Compaq, and Hewlett Packard.
Minicomputers
In 1957, the first of the major languages appeared in the form of
FORTRAN. Its name stands for FORmula TRANslating system. The
language was designed at IBM for scientific computing.
Although FORTAN was good at handling numbers, it was not so good
at handling input and output, which mattered most to business
computing. Business computing started to take off in 1959, and
because of this, COBOL (Common Business-Oriented Language) was
developed.
Programming Languages
Integrated CircuitsIn 1959, the first integrated circuit was created. Jack Kilby of Texas
Instruments and Robert Noyce of Fairchild Semiconductor, two separate
inventors, unaware of each other's activities, invented almost identical
integrated circuits at nearly the same time. An integrated circuit is an
assembly of electronic components fabricated in a single unit.
This is the PDP-1 – the first digital minicomputer with video display. It
was Digital Equipment Corporations first computer.
In 1964, IBM introduced the System/360, the first large "family" of
computers to use interchangeable software and peripheral equipment.
Rather than purchase a new system when the need and budget grew,
customers now could simply upgrade parts of their hardware. It was a
bold departure from the monolithic, one-size-fits-all mainframe.
Supercomputers
The 4004 was Intel's first microprocessor.
This breakthrough invention powered the
Busicom calculator and paved the way for
embedding intelligence in inanimate
objects including the personal computer.
1971: 4004 Microprocessor
In 1976, Steve Wozniak and Steve Jobs form Apple Computer and
show off the Apple I at the Homebrew Computer Club at Stanford
University.
The 80’sIn July of 1980, IBM representatives meet for the first time with Microsoft's Bill Gates to talk about writing an operating system for IBM's new hush-hush "personal" computer. The first IBM PC ran on a 4.77 MHz Intel 8088 microprocessor. The PC came equipped with 16 kilobytes of memory (expandable to 256k), one or two 160k floppy disk drives, an optional color monitor and a price tag starting at $1,565.
The Macintosh debuts in 1984. It features a simple, graphical
interface, uses the 8-MHz, 32-bit Motorola 68000 CPU, and has a
built-in 9-inch B/W screen.
Apple Computers
As its name implies, Windows 3 was not the first release of Microsoft's
Windows graphical user interface for PC's. Windows had originally been
released in 1985. However, in the past Windows had looked ugly, run slowly
and had very little support from third party software developers.
Microsoft Windows
mid 1950’s: assembly languages replaced numeric codes with mnemonic names
an assembler is a program that translates assembly code into machine code▪ input: assembly language program▪ output: machine language program
still low-level & machine-specific, but easier to program
32
gcc2_compiled.:
.global _Q_qtod
.section ".rodata"
.align 8
.LLC0: .asciz "Hello world!"
.section ".text"
.align 4
.global main
.type main,#function
.proc 04
main: !#PROLOGUE# 0
save %sp,-112,%sp
!#PROLOGUE# 1
sethi %hi(cout),%o1
or %o1,%lo(cout),%o0
sethi %hi(.LLC0),%o2
or %o2,%lo(.LLC0),%o1
call __ls__7ostreamPCc,0
nop
mov %o0,%l0
mov %l0,%o0
sethi %hi(endl__FR7ostream),%o2
or %o2,%lo(endl__FR7ostream),%o1
call
__ls__7ostreamPFR7ostream_R7ostream,0
nop
mov 0,%i0
b .LL230
nop
.LL230: ret
restore
.LLfe1: .size main,.LLfe1-main
.ident "GCC: (GNU) 2.7.2"
late 1950's – present:high-level languages allow the programmer to think at a higher-level of abstraction
a compiler is a program that translates high-level code into machine code
▪ input: C++ language program▪ output: machine language program▪ similar to assembler, but more complex
an interpreter is a program that reads and executes each language statement in sequence▪ Java programs are first compiled into a virtual machine language
(Java byte code)▪ then the byte code is executed by an interpreter (Java Virtual
