History of Data Processing
Processing data faster and faster has always been a part of any industrialized growth, and being able to
do it quickly and with little error is even better. What so many do not realize is that it doesn’t take a
computer to do any of this processing. Rather modern data processing can be done and was done for a
long time by the use of plain old everyday mechanical devices, certainly not fast or flashy, but done all
the same and done quite well.
Modern Data processing and information systems came about through Unit Record. Unit Record
operations lasted a long time, well over 70 years and there were, believe it or not, no computers
anywhere.
UNIT RECORD
Data Processing started out in a very physical way by first coming up with a system to store digital data
and then manipulating it. The introduction of punched card files solved the problem of storing digital
data. The second problem of data manipulation came in the way of a number of ingenious machines.
Such a storage system came unto use in 1890, many years before computers were reliable enough or
cheap enough. Unlike the theoretical and whiz-bang exploits of Babbage and Pascal, the type of data
storage first began by Herman Hollerith was not esoteric machinations involving wheels and cogs but
instead a very practical way to capture data and produce usable results. His inventions were quickly
adapted for businesses and government in a time when innovation was badly needed and certainly
utilized.
A Punch Card
Hollerith worked for the Census Department during the 1880 census and decided that he could develop
a better way to collect, store, summarize, and report census data rather than just doing it all by hand.
He designed a card that contained little punched holes. These holes represented digital information and
could be electronically tabulated by a machine that he also designed. The census of 1890 was
completed in just three years, much faster than the 1880 census.
By 1896 Hollerith had left the Census Department and struck out on his own, setting up a company that
by 1924 became IBM.
As time went on data processing had to grow to keep up with demand. In the subsequent evolution of
data processing there were at least four distinct technological advances or shall we refer to them as
generations.
Generations of Data Processing
Unit Record - The Zero generation
Unit Record is referred to as the zero generation of computer evolution, even though there were no
vacuum tubes or transistors involved, just switches, relays, capacitors, resistors, solenoids, and other
common electric circuits. The zero generation's building block was a card, the Unit Record, made of thin
yet stiff cardboard to allow it to be rapidly machine fed into card readers and then interpreted by
electronic brushes.
First generation
The advent of vacuum tube technology was the first visible modern step on computing. These first
generation computers did not work well and were not reliable and are today usually consigned to
museums or long ago gone into scrap heaps. The period remains pretty much a reminder of our hasty,
fervent but nonetheless failed efforts to improve information processing. But because of the war II, it
was more an attempt to do scientific applications and thus had little appeal to the more business
oriented needs of the day. The first generation was a primitive attempt at best and it offered little to
business. You could practically stand and watch a computer go through its cycles. The computer
language in use was machine based and was inscrutable to most people and had very little significance
on practical every day data processing.
Second generation
The advent of the solid state ushered in a better and most important, a cooler running computer. The
famous IBM 1401 and the much faster IBM 7090 series revolutionized computing to a great extent
although few mainline card oriented applications were immediately affected, and continued to use Unit
Record for their day to day work. With second generation technology however, there was greater
reliability and even an interest by the business community to look into new opportunities. But there
was still much to be desired with this next wave of computer technology. Programmers still needed to
use low level programming languages, in IBM's case called Autocoder. It was low level because it
generated machine code. Machine coding corresponds one for one with actual machine code,
sometimes referred to as “metal scratching”. The programmer had to have a good knowledge of just
how a computer machine decoded and executed it's instruction set.
The Third Generation
Improvements
I noticed some very striking advances with third generation computing technology. The whole idea of a
real and dramatic technological breakthrough seems to have been more than exemplified during those
critical years. Some advances came almost immediately in the wake of the IBM 360 series of computers.
Other advances arrived ten years later or so, but they were advances that truly set the third generation
up as great. Here is a partial list of what I feel were some of these fundamental improvements.
1. Device Independence. Computer programs no longer had to be too concerned about what form the
data was coming in or going out. It no longer mattered if it was on cards or tape or disk, since the form
of media was no longer at issue. This advantage was quite significant, because before device
independence, programs had to be programmed to handle the type of media on which data was read or
written. These different I/O operations could be significant, tedious, and error prone.
2. Program Relocatibility. Internal addressing in 360 architecture was indirect. Locations in core
memory used a sophisticated base plus displacement technique. When programs were loaded into
memory, they could be put anywhere since all the machine had to do was change the contents of the
base register.
3. Clear Command Structure Hierarchy. There was a definite hierarchy in the way the computer
functioned. It was like a general who gave orders to his majors who gave orders to their sergeants who
gave orders to their privates. If lower level failure occurred it did not damage the overall computer
functioning.
4. Operating Systems. With the third generation came a number of exceptionally good operating
systems that maintained overall control of the computer.
5. High level languages . Several very useful higher level languages had been developed by 1960, in
particular COBOL, a business language and FORTRAN, a scientific language. These languages allowed
much more freedom in software design and construction.
6. Program Modularity. An entire new concept began to emerge around this time about how to write
programs. The idea of bigger as better was being replaced by modularity. By making program functions
smaller and isolating functions they became more manageable.
7. Improved programming development techniques. New radical ideas such as "go-to-less" logic and
top-down design became the watchword, as managers realized that large programs were just too hard
to maintain.
8. Professional Recognition. By as early as 1970 the educational establishment began to recognize the
emergence and importance of computer science and systems programming. These disciplines were
beginning to assume professional significance, whereas before they were merely considered trades.
9. Emergence of modern data base concepts. A number of new ways to organized, access and update
data were developed during this time, including file structures like IDAM, HDAM, HIDAM. Entire data
base systems were developed to handle the movement toward online applications. The most famous
data base system was IMS (Information Management System), a basically hierarchical system and the
later relational DB2 system, which was quite similar to Oracle, both using the SQL protocol.
Types of Computers
1. Mainframe Computers
Mainframe computers are the big, powerful, expensive computers used in the background by most large
organizations.
2. Minicomputers
Like mainframes, these are very powerful and also very expensive. In many ways, the old differences
between a mainframe and a minicomputer have blurred and in many cases, the two words are almost
interchangeable.
3. Supercomputers
A super computer, as the name implies is an incredibly powerful beast with a phenomenal capacity for
processing data. They are used extensively by the military. In civilian use, they tend to be used for
research and also in areas such as weather forecasting where a tremendous amount of data has to be
processed rapidly and used to make predictions.
Examples:
K computer
Tianhe
Jaguar
IBM Roadrunner
Blue Gene/L
The Earth Simulator
ASCI White
ASCI Red
Fujitsu Numerical Wind Tunnel
CM-5/1024 At Los Alamos
4. Personal Computers
IBM invented the PC (Personal Computer) way back in 1981. All PCs released since then are in many
ways compatible with the original design, though many improvements to the original design have been
made. The term ‘PC compatible’ relates to PCs manufactured by companies other than IBM that are
compatible with the traditional PC specifications.
5. Laptop & Palmtop Computers
Laptop computers as the name implies are small, portable computers that can run on batteries as well
as mains power. They use special screens, rather than the traditional bulky VDUs (Visual Display Units).
Palmtop computers are even smaller than laptop computers.
Components of a Computer
Computers come in all different shapes and forms (examples: desktops, laptops), but the main
components that make up a computer pretty much stay the same. Components can also be referred to
as; hardware or parts. Throughout this website I will explain the various components in a PC computer,
and try my best to give you the information you need to better understand how your computer works.
Some of this information is considered basic computer knowledge, but there is no better place to start
with than with the basics. Knowing this valuable information can help you if you are going to buy, repair,
maintain or even build your own computer.
Every computer Consists of the following basic components:
1. Computer Case - Where all of the components are stored.
2. CPU - It is basically the brain of your computer. The CPU is a used to process everything
from basic to complex functions in a computer.
3. RAM - RAM is memory that attaches to the motherboard. RAM is hardware used to
temporarily store and access data.
4. Motherboard - A Motherboard is the most important component in a computer system.
All of the other hardware in a computer system connect to the motherboard.
5. Power Supply - A Power Supply is the sends power to all of the other hardware so they
can operate.
6. Hard Drive - A Hard Drive is used for permanently storing files and programs.
7. Disk Drives - Disk Drives can be a floppy drive, CD drive, DVD drive or other possible file
storage devices that are used in a computer.
8. Video Card - A Video Card is the part of a computer system that converts binary code
from the CPU so you can view it on a monitor.
9. Monitor - The part of a computer that allows you to see what the computer is processing.
10. Keyboard - A keyboard allows a computer user to enter text commands into a computer
system.
11. Mouse - A mouse allows a computer user to use a point and click interface to enter
commands.
The CPU
The CPU is the brain within your computer. It performs most of the calculations and is responsible for
the smooth running of your operating system (Microsoft Windows) as well as your application programs,
such as word-processors, spreadsheets and databases. There is a small amount of memory associated
with the CPU, which it uses to perform these operations. It also accesses and uses the main memory
(RAM - Random Access Memory) within your computer.
In many ways, the CPU is the most important item within your computer that governs the overall speed
of your computer. The speed of the CPU is measured in MHz. This relates to the frequency that the CPU
runs at and the higher the MHz rating of your CPU the faster your computer will run. To give you some
indication of how PCs have advanced over the years, the original IBM PC released in 1981 ran at 4.77
MHz while modern PCs run at speeds in excess of 800 MHz!
Memory
RAM
The Random Access Memory (RAM) is the main 'working' memory used by the computer. When you
first switch on the computer, the operating system (OS) loads from the Hard disk to the RAM.
The original IBM PC could only use up to 640 KB of memory (just over half a megabyte), whereas a
modern computer can effectively house, as much RAM as you can afford to buy! Commonly modern
computers are supplied with over 64 MB of RAM. As a rough rule, a Microsoft Windows based
computer will operate faster if you install more RAM. Data and programs stored in the RAM are volatile
(i.e. the information is lost when you switch off the computer).
ROM
Read Only Memory (ROM) as the name suggests is a special type of memory chip from which existing
software can be read but not written to. A good example is the ROM-BIOS chip, which contains readonly software. Often network cards and video cards also contain ROM chips.
Video (graphics) memory
The picture that you see on your screen is a form of data and this data has to be stored somewhere.
The on-screen pictures are held in special memory chips called video memory chips. These chips are
usually located on the video card. A modern computer will be supplied with several Megabytes of video
memory.
Input/ Output and Storage Devices
Input devices are used to enter commands and data into the computer. Output devices are used to let
the user know the results of the entered commands.
The memory of a computer is volatile. Therefore, a user needs to store the data in the memory to a
non-volatile device so that they can be accessed again. Storage devices are used for this purpose.
Input/output and storage devices do not work just because the relevant hardware is connected to the
computer. The corresponding software (generally called device drivers) need to be installed so that
these devices can function properly.
Input Devices
Keyboards
The keyboard is still the most common way of entering information into a computer.
There are a number of different types of keyboards, including those specially designed to use
with Microsoft Windows.
Mice
The mouse came into common use on a PC with the introduction of the Microsoft Windows
operating system. There are many different types of mice, a commonly used model now has a
small wheel on it which, when combined with the correct software allows additional functions
and fine control over the use of your applications.
Touch Pads
A touch pad is a device that lies on the desktop and responds to pressure. Used in conjunction
with a special pen they can be used by graphic artists, who wish to create original digital
artwork.
Light Pens
A light pen is used to allow users to point to areas on a screen and is often used to select menu
choices.
Joysticks
Many games require a joystick for the proper playing of the game. There are many different
types, the more sophisticated respond to movement in 3 axis directions, as well as have a
number of configurable buttons.
Voice-Input Devices
Voice-input devices convert a person's spoken words to digital code. Combined with
appropriate software, these devices are part of the voice recognition system that allows users
to operate microcomputers using voice commands.
Scanners
A scanner allows you to scan printed material and convert it into a file format that may be used
within the PC. You can scan pictures and then manipulate these inside the PC using a graphics
application of your choice. In addition, you can scan printed text and convert this not just to a
picture of the text but also to actual text that can be manipulated and edited as text within your
word-processor. There are a number of specialist programs, generically called OCR (Optical
Character Recognition) programs, which are specifically designed for converting printed text
into editable text within your applications.
Output Devices
VDUs (computer monitor or screen)
The VDU (Visual Display Unit) is the computer screen used to output information in an
understandable format for humans.
There are two types CRT and LCD. LCD is less power and space consuming monitor type that popular
now.
Terminals
A terminal is an input/output device that connects to a host computer or server. Terminals are
of four types:
Dumb--sends and receives only; does no processing.
Intelligent--has a processing unit, memory, and secondary storage.
Network--network computers (thin clients) are low cost alternatives to intelligent terminals
Internet--(Web terminals) accesses Internet and displays on the television set.
Printers
Output from a display screens is called a soft copy. Output from a printer is called a hard copy.
The four types of printers are:
Ink-jet--sprays droplets of ink on paper. It is good for color printing and provides very
good quality.
Laser--uses a technology like in photocopiers. Lasers print high-quality text and graphics.
Dot matrix--forms text and graphic images with a matrix of pins.
Thermal--heat elements produce images on special heat-sensitive paper. Expensive.
Produces very high quality art and design output.
Storage Devices
Devices that are used to store or back up data. To measure the capacity of the storage device or the
consumption of the space by data a unit is used. The smallest unit is Byte.
1000 Bytes = 1 Kilo Bytes (KB)
1000 Kilo Bytes = 1 Mega Bytes (MB)
1000 Mega Bytes = 1 Giga Bytes (GB)
1000 Giga Bytes = 1 Terabytes (TB)
Floppy Disks
Floppy disks (disks, diskettes) are circular plastic disks. 3 1/2-inch 2HD disks have a 1.44
megabyte capacity.
Hard Disks
A hard disk is an enclosed disk drive that contains one or more metallic disks. Enclosing the disk
in a sealed container prevents entering of material that could cause a head crash. Hard disks
have far more capacity than floppy disks do.
Hard disks come in three forms:
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An internal hard disk has one or more metallic platters sealed inside a container.
Hard-disk cartridges can be removed when they are filled or transported.
Mini and mainframe computers use hard-disk packs, which are hard disks consisting
of several platters in a stack.
Optical Disks
An optical disk is a metallic disk that uses a laser beam for reading and writing. Four kinds are:
CD-ROM (compact disc read-only memory) : cannot be written on or erased by user (read-only). Used to
distribute large databases, reference materials, and software.
CD-R (CD-recordable) or WORM (write once, read many): can be written to one time, after which it
cannot be erased by users but can be read many times without deterioration.
Erasable optical disks: can be written on and erased and reused. Two basic types: CD-RW (compact disk
re-writeable) and MO (magnetic optical).
DVD (digital versatile disk): similar to CDs. Have a greater capacity of 4.7 gigabytes.
Blue Ray Disk- An optical disc storage medium designed to supersede the DVD format
DESCRIPTION
CAPACITY
CD-ROM
650 MB
CD-R
600 - 650 MB
Erasable
600 - 1000 MB
DVD
4.7 GB
Blue Ray Disk
25 GB- 125 GB…
Magnetic Tapes
Magnetic tape storage is mainly used to back up (duplicate) programs and data on disks. Two
forms are:
Magnetic Tape Streamers (backup tape cartridge units) consist of tape cartridges used
to back up microcomputer hard disks.
Magnetic Tape Reels, used to back up mini and mainframe computer storage. Run on
magnetic drives (magnetic tape units).
Pen Drives
Pen drives are fast becoming a common storage device. These are very high capacity portable
devices that can be plugged directly into the USB port which is available in most modern day
computers. These are also called flash drives.
Comparison of Storage Devices
TYPE
ADVANTAGE
DISADVANTAGE
TYPICAL USE
Floppy disk
Low capacity, slow
Inexpensive, direct access
access
Store files for word
processors and
spreadsheets
Hard disk
Fast, direct access
Limited capacity
Store programs and
data
CD-ROM
High capacity, direct
access
Slow access
Reference material
Magnetic
tape
High capacity
Slow sequential data
access
Backup programs
and data
Computer system
A complete, working computer. Computer systems will include the computer along with any software
and peripheral devices that are necessary to make the computer function. Every computer system, for
example, requires an operating system.
Business Computer System
A Computer system that is loaded with components and dedicated tool s (software) to perform business
operations and Storage devices and tools to back up critical data.
The tools and components depend on the business type. For some systems beside tools communication
methods like network or internet connectivity may needed.
File and computer safety
To protect a computer system, the hardware components can be protected from physical thefts by
applying security methods like keeping the system in a safe place protected by walls, people etc.
To protect data a software based method must be used.
If the system is protected from physical thefts the data can be damaged by people or thefts like virus
attack. To protect from people a protection method like password protection, user restriction can be
used. Protect from virus attack software called antivirus programs can be used.
Computer Virus
A computer virus is a computer program that can replicate itself and spread from one computer to
another.
Virus can be spread by
Internet, E-mail (Network)
Storage Devices (Hard Disks, Pen Drives, Optical Drives )
Attack types of Virus programs
System Sectors/Boot Records - Viruses can infect the parts of the system that are used to run programs
and perform functions such as startup and shut down.
Files - Viruses can infect program files or delete files. These viruses stick to program files such as .com,
.exe, .sys, etc. Some viruses hide in the memory of the computer at first, while others simply attack a
specific software program, such as Microsoft Word.
Companion Files - Viruses can create companion files that are a special type of file that adds files that
run on the hard disk.
Macros - Viruses can infect macro or data files.
Disk Clusters - Viruses can infect files through the disk directory.
Batch Files - Viruses can use batch files to infect a computer.
Source Code - Viruses can be in additional code that is added to actual program source code.
Visual Basic Worms - These worms use the Visual Basic programming language to control a computer
and perform tasks.
Virus Types
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Resident Viruses
Direct Action Viruses
Overwrite Viruses
Boot Virus
Macro Virus
Directory Virus
Polymorphic Virus
File Infectors Companion Viruses
FAT Virus
Worms
Trojans or Trojan Horses
Logic Bombs
Symptoms of a Virus Infection
In a Computer
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Slower than usual. Stops responding or it locks up frequently.
Crashes, restarts.
Applications on the computer do not work correctly.
Disk drives are inaccessible.
Cannot print items correctly.
Unusual error messages.
Distorted menus and dialog boxes.
Double extensions such as a .jpg, .vbs, .gif, or .exe. extension.
An antivirus program is disabled for no reason. Additionally, the antivirus program cannot
be restarted.
An antivirus program cannot be installed on the computer, or the antivirus program will not
run.
New icons appear on the desktop.
Strange sounds or music plays from the speakers unexpectedly.
A program disappears.
In a Storage Device
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On double click an auto run starts.
Unknown filed or folders.
Show lower capacity without contents
Safe Computing Practices
Anti-Virus Software - If you don't have an anti-virus software program, invest in one.
Scan Your Computer on a Regular Basis - Scan you system with anti-virus software regularly.
Update Your Anti-Virus Software on a Regular Basis - Keep your anti-virus software up to date. Do this
at least weekly and more often if there are news reports of a new virus threat.
Backup - Backup your files on a regular basis. Always maintain copies of files you can't do without, just in
case your computer gets infected and crashes.
Turn off E-Mail Preview - Turn off the preview function if your e-mail software has one.
Scan Removable Disks (Floppy, CD, Pen) - Scan Removable disks from other computers with anti-virus
software before you use the disk. Simply place the disk in your f drive and run the anti-virus software
program. If a virus is found, most programs will give you several choices about what to do, such as
removing the virus, doing nothing, or deleting the file that contains the virus.
Protect Your Disks - Write-protect any disk you place into another computer. If the other computer has
a boot sector virus, the write-protect on the disk will prevent it from becoming infected with the virus.
Scan Downloaded Files - Scan downloaded Internet files with anti-virus software before you use or run
them.
Scan All E-Mail Attachments - If you receive an attachment you need to view, scan it with anti-virus
software before you open it.
Beware of E-Mail Attachments from Unknown Sources - If you receive an unexpected attachment from
an unknown source, delete it. Never open attachments for files that end in .vbs (Visual Basic Script) or .js
(Java Script). Viruses often travel in these types of files.
Be Alert - Pay attention to news about virus alerts. You might want to subscribe to a virus alert e-mail
notice from one of the anti-virus software makers.