The Comparative Analysis Of The History Of The Computer Science And The Computer Engineering In The USA And Ukraine
The Comparative Analysis Of The
History Of The Computer Science And The Computer Engineering In The
USA And Ukraine.
HOWARD H.
AIKEN AND THE COMPUTER
Howard Aiken's contributions to the
development of the computer -notably the Harvard Mark I (IBM ASSC)
machine, and its successor the Mark II - are often excluded from the
mainstream history of computers on two technicalities. The first is
that Mark I and Mark II were electro-mechanical rather than
electronic; the second one is that Aiken was never convinced that
computer programs should be treated as data in what has come to be
known as the von Neumann concept, or the stored program.
It is not
proposed to discuss here the origins and significance of the stored
program. Nor I wish to deal with the related problem of whether the
machines before the stored program were or were not “computers”.
This sub>ject is complicated by the confusion in actual names given to
machines. For example, the ENIAC, which did not incorporate a stored
program, was officially named a computer: Electronic Numeral
Integrator And Computer. But the first stored-program machine to be
put into regular operation was Maurice Wiles' EDSAC: Electronic Delay
Storage Automatic Calculator. It seems to be rather senseless to deny
many truly significant innovations (by H.H.Aiken and by Eckert and
Mauchly), which played an important role in the history of computers,
on the arbitrary ground that they did not incorporate the
stored-program concept. Additionally, in the case of Aiken, it is
significant that there is a current computer technology that does not
incorporate the stored programs and that is designated as (at least
by TEXAS INSTRUMENTS)
as “Harvard architecture”, though, it should more properly be
called “Aiken architecture”. In this technology the program is
fix and not sub>ject to any alteration save by intent - as in some
computers used for telephone switching and in ROM.
OPERATION
OF
THE ENIAC.
Aiken
was a visionary, a man ahead of his times. Grace Hopper and others
remember his prediction in the late 1940s, even before the vacuum
tube had been wholly replaced by the transistor, that the time would
come when a machine even more powerful than the giant machines of
those days could be fitted into a space as small as a shoe box.
Some
weeks before his death Aiken had made another prediction. He pointed
out that hardware considerations alone did not give a true picture of
computer costs. As hardware has become cheaper, software has been apt
to get more expensive. And then he gave us his final prediction: “The
time will come”, he said, “when manufacturers will gave away
hardware in order to sell software”. Time alone will tell whether
or not this was his final look ahead into the future.
DEVELOPMENT OF
COMPUTERS IN THE USA
In the early 1960s, when computers were
hulking mainframes that took up entire rooms, engineers were already
toying with the then - extravagant notion of building a computer
intended for the sole use of one person. by the early 1970s,
researches at Xerox's Polo Alto Research Center (Xerox PARC) had
realized that the pace of improvement in the technology of
semiconductors - the chips of silicon that are the building blocks of
present-day electronics - meant that sooner or later the PC would be
extravagant no longer. They foresaw that computing power would
someday be so cheap that engineers would be able to afford to devote
a great deal of it simply to making non-technical people more
comfortable with these new information - handling tools. in their
labs, they developed or refined much of what constitutes PCs today,
from “mouse” pointing devices to software “windows”.
Although
the work at Xerox PARC was crucial, it was not the spark that took
PCs out of the hands of experts and into the popular imagination.
That happened inauspiciously in January 1975, when the magazine
Popular Electronics
put a new kit for hobbyists, called the Altair, on its cover. for the
first time, anybody with $400 and a soldering iron could buy and
assemble his own computer. The Altair inspired Steve Wosniak and
Steve Jobs to build the first Apple computer, and a young college
dropout named Bill Gates to write software for it. Meanwhile. the
person who deserves the credit for inventing the Altair, an engineer
named Ed Roberts, left the industry he had spawned to go to medical
school. Now he is a doctor in small town in central Georgia.
To
this day, researchers at Xerox and elsewhere pooh-pooh the Altair as
too primitive to have made use of the technology they felt was needed
to bring PCs to the masses. In a sense, they are right. The Altair
incorporated one of the first single-chip microprocessor - a
semiconductor chip, that contained all the basic circuits needed to
do calculations - called the Intel 8080. Although the 8080 was
advanced for its time, it was far too slow to support the mouse,
windows, and elaborate software Xerox had developed. Indeed, it
wasn't until 1984, when Apple Computer's Macintosh burst onto the
scene, that PCs were powerful enough to fulfill the original vision
of researchers. “The kind of computing that people are trying to do
today is just what we made at PARC in the early 1970s,” says Alan
Kay, a former Xerox researcher who jumped to Apple in the early
1980s.
MACINTOSH PERFORMA 6200/6300
Researchers today are
proceeding in the same spirit that motivated Kay and his Xerox PARC
colleagues in the 1970s: to make information more accessible to
ordinary people. But a look into today's research labs reveals very
little that resembles what we think of now as a PC. For one thing,
researchers seem eager to abandon the keyboard and monitor that are
the PC's trademarks. Instead they are trying to devise PCs with
interpretive powers that are more humanlike - PCs that can hear you
and see you, can tell when you're in a bad mood and know to ask
questions when they don't understand something.
It is impossible
to predict the invention that, like the Altair, crystallize new
approaches in a way that captures people's imagination.
Top 20 computer
systems
From soldering irons to SparcStations, from
MITS to Macintosh, personal computers have evolved from
do-it-yourself kits for electronic hobbyists into machines that
practically leap out of the box and set themselves up. What enabled
them to get from there to here? Innovation and determination. Here
are top 20 systems that made that rapid evolution possible.
MITS
Altair 8800
There once was a time when you
could buy a top-of-the-line computer for $395. The only catch was
that you had to build it yourself. Although the Altair 8800 wasn't
actually the first personal computer (Scelbi Computer Consulting`s
8008-based Scelbi-8H kit probably took that honor in 1973), it
grabbed attention. MITS sold 2000 of them in 1975 - more than any
single computer before it.
Based on Intel`s 8-bit 8080 processor,
the Altair 8800 kit included 256 bytes of memory (upgradable, of
course) and a toggle-switch-and-LED front panel. For amenities such
as keyboard, video terminals, and storage devices, you had to go to
one of the companies that sprang up to support the Altair with
expansion cards. In 1975, MITS offered 4- and 8-KB Altair versions of
BASIC, the first product developed by Bill Gates` and Paul Allen`s
new company, Microsoft.
If the personal computer hobbyists
movement was simmering, 1975 saw it come to a boil with the
introduction of the Altair 8800.
Apple
II
Those
of you who think of the IBM PC as the quintessential business
computers may be in for a surprise: The Apple II (together with
VisiCalc) was what really made people to look at personal computers
as business tools, not just toys.
The Apple II debuted at the
first West Coast Computer Fair in San Francisco in 1977. With
built-in keyboard, graphics display, eight readily accessible
expansion slots, and BASIC built-into ROM, the Apple II was actually
easy to use. Some of its innovations, like built-in high-resolution
color graphics and a high-level language with graphics commands, are
still extraordinary features in desk top machines.
With a 6502
CPU, 16 KB of RAM, a 16-KB ROM, a cassette interface that never
really worked well (most Apple It ended up with the floppy drive the
was announced in 1978), and color graphics, the Apple II sold for
$1298.
Commondore PET
Also
introduced at the first West Coast Computer Fair, Commondore`s PET
(Personal Electronic Transactor) started a long line of expensive
personal computers that brought computers to the masses. (The VIC-20
that followed was the first computer to sell 1 million units, and the
Commondore 64 after that was the first to offer a whopping 64 KB of
memory.)
The keyboard and small monochrome display both fit in the
same one-piece unit. Like the Apple II, the PET ran on MOS
Technology's 6502. Its $795 price, key to the Pet's popularity
supplied only 4 KB of RAM but included a built-in cassette tape drive
for data storage and 8-KB version of Microsoft BASIC in its 14-KB
ROM.
Radio Shack TRS-80
Remember
the Trash 80? Sold at local Radio Shack stores in your choice of
color (Mercedes Silver), the TRS-80 was the first ready-to-go
computer to use Zilog`s Z80 processor.
The base unit was
essentially a thick keyboard with 4 KB of RAM and 4 KB of ROM (which
included BASIC). An optional expansion box that connected by ribbon
cable allowed for memory expansion. A Pink Pearl eraser was standard
equipment to keep those ribbon cable connections clean.
Much of
the first software for this system was distributed on audiocassettes
played in from Radio Shack cassette recorders.
Osborne
1 Portable
By the end of the 1970s, garage
start-ups were pass. Fortunately there were other entrepreneurial
possibilities. Take Adam Osborne, for example. He sold Osborne Books
to McGraw-Hill and started Osborne Computer. Its first product, the
24-pound Osborne 1 Portable, boasted a low price of $1795.
More
important, Osborne established the practice of bundling software - in
spades. The Osborne 1 came with nearly $1500 worth of programs:
WordStar, SuperCalc, BASIC, and a slew of CP/M utilities.
Business
was looking good until Osborne preannounced its next version while
sitting on a warehouse full of Osborne 1S. Oops. Reorganization under
Chapter 11 followed soon thereafter.
Xerox
Star
This is the system that launched a
thousand innovations in 1981. The work of some of the best people at
Xerox PARC (Palo Alto Research Center) went into it. Several of these
- the mouse and a desktop GUI with icons - showed up two years later
in Apple`s Lisa and Macintosh computers. The Star wasn't what you
would call a commercial success, however. The main problem seemed to
be how much it cost. It would be nice to believe that someone shifted
a decimal point somewhere: The pricing started at $50,000.
IBM
PC
Irony of ironies that someone at
mainframe-centric IBM recognized the business potential in personal
computers. The result was in 1981 landmark announcement of the IBM
PC. Thanks to an open architecture, IBM's clout, and Lotus 1-2-3
(announced one year later), the PC and its progeny made business
micros legitimate and transformed the personal computer world.
The
PC used Intel`s 16-bit 8088, and for $3000, it came with 64 KB of RAM
and a 51/>4>-inch
floppy drive. The printer adapter and monochrome monitor were extras,
as was the color graphics adapter.
Compaq
Portable
Compaq's Portable almost
single-handedly created the PC clone market. Although that was about
all you could do with it single-handedly - it weighed a ton. Columbia
Data Products just preceded Compaq that year with the first true IBM
PC clone but didn't survive. It was Compaq's quickly gained
reputation for engineering and quality, and its essentially 100
percent IBM compatibility (reverse-engineering, of course), that
legitimized the clone market. But was it really designed on a
napkin?
Radio Shack TRS-80 Model
100
Years before PC-compatible sub>notebook
computers, Radio Shack came out with a book-size portable with a
combination of features, battery life, weight, and price that is
still unbeatable. (Of course, the Z80-based Model 100 didn't have to
run Windows.)
The $800 Model 100 had only an 8-row by 40-column
reflective LCD (large at the time) but supplied ROM-based
applications (including text editor, communications program, and
BASIC interpreter), a built-in modem, I/O ports, nonvolatile RAM, and
a great keyboard. Wieghing under 4 pounds, and with a battery life
measured in weeks (on four AA batteries), the Model 100 quickly
became the first popular laptop, especially among journalists.
With
its battery-backed RAM, the Model 100 was always in standby mode,
ready to take notes, write a report, or go on-line. NEC`s PC 8201 was
essentially the same Kyocera-manufectured system.
Apple
Macintosh
Whether you saw it as a
seductive invitation to personal computing or a cop-out to wimps who
were afraid of a command line, Apple`s Macintosh and its GUI
generated even more excitement than the IBM PC. Apple`s R&D
people were inspired by critical ideas from Xerox PARK (and practiced
on Apple`s Lisa) but added many of their own ideas to create a
polished product that changed the way people use computers.
The
original Macintosh used Motorola's 16-bit 68000 microprocessor. At
$2495, the system offered a built-in-high-resolution monochrome
display, the Mac OS, and a single-button mouse. With only 128 KB of
RAM, the Mac was underpowered at first. But Apple included some key
applications that made the Macintosh immediately useful. (It was
MacPaint that finally showed people what a mouse is good for.)
IBM
AT
George Orwell didn't foresee the AT in
1984. Maybe it was because Big Blue, not Big Brother, was playing its
cards close to its chest. The IBM AT set new standards for
performance and storage capacity. Intel`s blazingly fast 286 CPU
running at 6 MHz and 16-bit bus structure gave the AT several times
the performance of previous IBM systems. Hard drive capacity doubled
from 10 MB to 20 MB (41 MB if you installed two drives - just donut
ask how they did the math), and the cost per megabyte dropped
dramatically.
New 16-bit expansion slots meant new (and faster)
expansion cards but maintained downward compatibility with old 8-bit
cards. These hardware changes and new high-density 1.2-MB floppy
drives meant a new version of PC-DOS (the dreaded 3.0).
The price
for an AT with 512 KB of RAM, a serial/parallel adapter, a
high-density floppy drive, and a 20-MB hard drive was well over $5000
- but much less than what the pundits expected.
Commondore
Amiga 1000
The Amiga introduced the world
to multimedia. Although it cost only $1200, the 68000-based Amiga
1000 did graphics, sound, and video well enough that many broadcast
professionals adopted it for special effects. Its sophisticated
multimedia hardware design was complex for a personal computer, as
was its multitasking, windowing OS.
Compaq
Deskrpo 386
While IBM was busy developing
(would “wasting time on” be a better phrase?) proprietary Micro
Channel PS/2 system, clone vendors ALR and Compaq wrestled away
control of the x86 architecture and introduced the first 386-based
systems, the Access 386 and Deskpro 386. Both systems maintained
backward compatibility with the 286-based AT.
Compaq's Deskpro 386
had a further performance innovation in its Flex bus architecture.
Compaq split the x86 external bus into two separate buses: a
high-speed local bus to support memory chips fast enough for the
16-MHz 386, and a slower I/O bus that supported existing expansion
cards.
Apple Macintosh II
When
you first looked at the Macintosh II, you may have said, “But it
looks just like a PC. ”You would have been right. Apple decided it
was wiser to give users a case they could open so they could upgrade
it themselves. The monitor in its 68020-powered machine was a
separate unit that typically sat on top of the CPU case.
Next
Nextstation
UNIX had never been easy to
use , and only now, 10 years later, are we getting back to that
level. Unfortunately, Steve Job's cube never developed the software
base it needed for long-term survival. Nonetheless, it survived as an
inspiration for future workstations.
Priced at less than $10,000,
the elegant Nextstation came with a 25-MHz 68030 CPU, a 68882 FPU, 8
MB of RAM, and the first commercial magneto-optical drive (256-MB
capacity). It also had a built-in DSP (digital signal processor). The
programming language was object-oriented C, and the OS was a version
of UNIX, sugarcoated with a consistent GUI that rivaled Apple`s.
NEC
UltraLite
Necks UltraLite is the portable
that put sub>notebook
into the lexicon. Like Radio Shack's TRS-80 Model 100, the UltraLite
was a 4-pounder ahead of its time. Unlike the Model 100, it was
expensive (starting price, $2999), but it could run MS-DOS. (The
burden of running Windows wasn't yet thrust upon its shoulders.)
Fans
liked the 4.4-pound UltraLite for its trim size and portability, but
it really needed one of today's tiny hard drives. It used
battery-backed DRAM (1 MB, expandable to 2 MB) for storage, with
ROM-based Traveling Software's LapLink to move stored data to a desk
top PC.
Foreshadowing PCMCIA, the UltraLite had a socket that
accepted credit-card-size ROM cards holding popular applications like
WordPerfect or Lotus 1-2-3, or a battery-backed 256-KB RAM card.
Sun
SparcStation 1
It wasn't the first RISK
workstation, nor even the first Sun system to use Sun's new SPARC
chip. But the SparcStation 1 set a new standard for
price/performance, churning out 12.5 MIPS at a starting price of only
$8995 - about what you might spend for a fully configured Macintosh.
Sun sold lots of systems and made the words SparcStation
and workstation
synonymous in many peoples minds.
The SparcStation 1 also
introduced S-Bus, Sun's proprietary 32-bit synchronous bus, which ran
at the same 20-MHz speed as the CPU.
IBM
RS/6000
Sometimes, when IBM decides to do
something, it does it right.(Other times... Well, remember the PC
jr.?)The RS/6000 allowed IBM to enter the workstation market. The
RS/6000`s RISK processor chip set (RIOS) racked up speed records and
introduced many to term suprscalar.
But its price was more than competitive. IBM pushed third-party
software support, and as a result, many desktop publishing, CAD, and
scientific applications ported to the RS/6000, running under AIX,
IBM's UNIX.
A shrunken version of the multichip RS/6000
architecture serves as the basis for the single-chip PowerPC, the
non-x86-compatible processor with the best chance of competing with
Intel.
Apple Power Macintosh
Not
many companies have made the transition from CISC to RISK this well.
The Power Macintosh represents Apple`s well-planned and successful
leap to bridge two disparate hardware platforms. Older Macs run
Motorola's 680x0 CISK line, which is running out of steam; the Power
Macs run existing 680x0-based applications yet provide Power PC
performance, a combination that sold over a million systems in a
year.
IBM ThinkPad 701C
It
is not often anymore that a new computer inspires gee-whiz sentiment,
but IBM's Butterfly sub>notebook does, with its marvelous expanding
keyboard. The 701C`s two-part keyboard solves the last major piece in
the puzzle of building of usable sub>notebook: how to provide
comfortable touch-typing.(OK, so the floppy drive is sill
external.)
With a full-size keyboard and a 10.4-inch screen, the
4.5-pound 701C compares favorably with full-size notebooks. Battery
life is good, too.
The development of
computers in ukraine and the former USSR
The government and the authorities had paid
serious attention to the development of the computer industry right
after the Second World War. The leading bodies considered this task
to be one of the principal for the national economy.
Up to the
beginning of the 1950s there were only small productive capacities
which specialized in the producing accounting and account-perforating
(punching) machines. The electronic numerical computer engineering
was only arising and the productive capacities for it were close to
the naught.
The first serious steps in the development of
production base were made initially in the late 1950s when the work
on creating the first industry samples of the electronic counting
machines was finished and there were created M-20, “Ural-1”,
“Minsk-1”, which together with their semi-conductor successors
(M-220, “Ural-11-14”, “Minsk-22” and “Minsk-32”) created
in the 1960s were the main ones in the USSR until the computers of
the third generation were put into the serial production, that is
until the early 1970s.
In the 1960s the science-research and
assembling base was enlarged. As the result of this measures, all
researches connected with creating and putting into the serial
production of semi-conductor electronic computing machines were
almost finished. That allowed to stop the production of the first
generation machines beginning from the 1964.
Next decades the
whole branch of the computer engineering had been created. The
important steps were undertaken to widen the productive capacities
for the 3d
generation machines.
Kiev
the
homecity of mesm
MESM was conceived by S.A.Lebedev to be a
model of a Big Electronic Computing Machine (BESM). At first it was
called the Model of
the Big Electronic Computing Machine, but ,later, in the process of
its creation there appeared the evident expediency of transforming it
in a small computer. For that reason there were added: the
impute-output devices, magnetic drum storage, the register capacity
was enhanced; and the word “Model”
was changed for “Malaya”
(Small).
S.A.Lebedev was proposed to head the Institute of
Energetics in Kiev. After a year; when the Institute of was divided
into two departments: the electronical one and the department of
heat-and-power engineering, Lebedev became the director of the first
one. He also added his laboratory of analogue computation to the
already existing ones of the electronical type. At once he began to
work on computer science instead of the usual, routine researches in
the field of engineering means of stabilization and structures of
automated devices. Lebedev was awarded the State Prize of the USSR.
Since autumn 1948 Lebedev directed his laboratory towards creating
the MESM. The most difficult part of the work was the practical
creation of MESM. It might be only the many-sided experience of the
researches that allowed the scientist to fulfill the task perfectly;
whereas one inaccuracy was made: the hall at the ground-floor of a
two-storied building was assigned for MESM and when, at last, the
MESM was assembled and switched on, 6,000 of red-hot electronic lamps
created the “tropics” in the hall, so they had to remove a part
of the ceiling to decrease the temperature.
In autumn 1951 the
machine executed a complex program rather stabile.
ÒÍÅ MESM
WITH SOME OF THE PERSONAL (KIEV, 1951)
Finally all the tests were
over and on December, 15 the MESM was put into operation.
If to
remember those short terms the MESM was projected, assembled, and
debugged - in two years - and taking into consideration that only 12
people (including Lebedev) took part in the creating who were helped
by 15 engineers we shall see that S.A.Lebedev and his team
accomplished a feat (200 engineers and many workers besides 13 main
leaders took part in the creation of the first American computer
ENIAC).
As life have showed the foundations of the
computer-building laid by Lebedev are used in modern computers
without any fundamental changes. Nowadays they are well known:
such devices an arithmetic and memory input-output and control ones should be a part of a computer architecture;
the program of computing is encoded and stored in the memory as numbers;
the binary system should be used for encoding the numbers and commands;
the computations should be made automatically basing on the program stored in the memory and operations on commands;
besides arithmetic, logical operations are used: comparisons, conjunction, disjunction, and negation;
the hierarchy memory method is used;
the numerical methods are used for solving the tasks.
The
main fault of The 70s
or
the years of “might-have-been
hopes”
The great accumulated experience in
creating computers, the profound comparison of our domestic
achievements with the new examples of foreign computer technique
prompted the scientists that it is possible to create the computing
means of new generation meeting the world standards. Of that opinion
were many outstanding Ukrainian scientists of that time - Lebedev,
Dorodnitsin, Glushkov and others. They proceeded from quite a
favorable situation in the country.
The computerization of
national economy was considered as one of the most essential tasks.
The decision to create the United system of computers - the machines
of new generation on integrals.
The USA were the first to create
the families of
computers. In 1963-64 the IBM Company worked out the IBM-360 system.
It comprised the models with different capacities for which a wide
range of software was created.
A decision concerning the third
generation of computers (their structure and architecture) was to be
made in the USSR in the late 60s.
But instead of making the
decision based on the scientific grounds concerning the future of the
United system of computers the Ministry of Electronic Industry issued
the administrative order to copy the IBM-360 system. The leaders of
the Ministry did not take into consideration the opinion of the
leading scientists of the country.
Despite the fact that there
were enough grounds for thinking the 70s would bring new big
progresses, those years were the step back due to the fault way
dictated by the highest authorities from above.
The
comparison of the computer development
in the usa and ukraine
At the time when the computer science was just uprising
this two countries were one of the most noticeably influential. There
were a lot of talented scientists and inventors in both of them. But
the situation in Ukraine (which at that time was one of 15 Republics
of the former USSR) was complicated, on one hand, with the
consequences of the Second World War and, on the other hand, at a
certain period Cybernetics and Computer Science were not
acknowledged. Of cause, later it went to the past, but nevertheless
it played a negative role on the Ukrainian computer development.
It
also should be noticed that in America they paid more attention to
the development of computers for civil and later personal use. But in
Ukraine the attention was mainly focused on the military and
industrial needs.
Another interesting aspect of the Ukrainian
computer development was the process of the 70s when “sovietizing”
of the IBM-360 system became the first step on the way of weakening
of positions achieved by the Soviet machinery construction the first
two decades of its development. The next step that led to the further
lag was the mindless copying by the SU Ministry of Electronic
Industry and putting into production the next American elaborations
in the field of microprocessor equipment.
The natural final stage
was buying in enormous quantities of foreign computers last years and
pressing to the deep background our domestic researches, and
developments, and the computer-building industry on the
whole.
Another interesting aspect of the Ukrainian computer
development was the process of the 70s when the “sovietising” of
the IBM-360 system became the first step on the way of weakening of
positions, achieved by the Soviet machinery construction of the first
two decades of its development. The next step that led to the further
lag was the mindless copying of the next American elaborations in the
field of microprocessor technique by the Ministry of Computer
Industry.
CONCLUSION
Having
analyzed the development of computer science in two countries I have
found some similar and some distinctive features in the arising of
computers.
First of all, I would like to say that at the first
stages the two countries rubbed shoulders with each other. But then,
at a certain stage the USSR was sadly mistaken having copied the
IBM-360 out of date technology. Estimating the discussion of possible
ways of the computer technique development in the former USSR in late
1960s - early 1970s from the today point of view it can be noticed
that we have chosen a worse if not the worst one. The only
progressive way was to base on our domestic researches and to
collaborate with the west-European companies in working out the new
generation of machines. Thus we would reach the world level of
production, and we would have a real base for the further development
together with leading European companies.
Unfortunately the last
twenty years may be called the years of “unrealized possibilities”.
Today it is still possible to change the situation; but tomorrow it
will be too late.
Will the new times come? Will there be a new
renaissance of science, engineering and national economy as it was in
the post-war period? Only one thing remains for us - that is to wait,
to hope and to do our best to reach the final goal.
bibliography:
Stephen G. Nash “A History of Scientific Computing”, ACM Press History Series, New York, 1990.
The America House Pro-Quest Database: “Byte” Magazine, September, 1995.
William Aspray, Charles Babbage Institute Reprint Series in the History of Computing 7, Los Angeles, 1985.
D.J.Frailey “Computer Architecture” in Encyclopedia of Computer Science.
Stan Augarten “Bit by Bit: An Illustrated History of Computers”, New York, 1984.
Michael R. Williams “A History of Computing Technology”, Englewood Cliffs, New Jersey, 1985.