computer software

Software consists of computer programs, which are sequences of instructions for the computer. It directs the computer system to perform specific information processing activities and that provide functionality for users.

The computer will do nothing until it is instructed by software. Although computer hardware is, by design, general purpose, software enables the user to instruct a computer system to perform specific functions that provide value. There are two major types of software: systems software and application software. The relationship among hardware, system software, and application software is illustrated below.

Systems Software

This provides important self-regulatory functions for computer systems, such as loading itself when the computer is first turned on, managing hardware resources such as secondary storage for all applications, and providing commonly used set of instructions for all applications to use.

Systems programs primarily manipulate computer hardware resources.

It controls and supports the computer system and its information processing activities. It also facilitates the programming, testing, and debugging of computer programs. There are two groups based on functional categories:

1. System Control Programs

This controls the use of hardware, software, and data resources of a computer system. The main system control program is the OPERATING SYSTEM (OS). The OS supervises the overall operation of the computer, including the computer’s status and scheduling operations, which includes input and output processes. The OS provides services that include process management, virtual memory, file management, security, fault tolerance, and the user interface.

Examples of OS:

MS-DOS Windows 91/95/98/2000/CE/ ME/XP
IBM’s OS/2 MAC OS
UNIX Linux


2. System Support Programs

This supports the operations, management, and users of a computer system by providing a variety of support services.

Examples of System Support Programs

System utilizes – programs written to accomplish common tasks such as sorting records, checking of diskettes, creating directories, and restores accidentally erased files.

System performance monitors – programs that monitor the processing of jobs on a computer system

System security monitors – programs that monitor the use of a computer system to protect it and its resources from unauthorized use, fraud, or destruction. It also provides security needed to allow only authorized users access to the system.

Application Software

This provides more specific functionality to users. That functionality maybe broad, such word processing or desktop publishing. An application program applies a computer to a certain need.

Application programs primarily manipulate data or text to produce or provide information.

Types of Application Software

1. Spreadsheets – transforms a computer screen into a ledger sheet, or grid, of coded rows and columns. Users can enter numeric or textual data into each grid location (cells). Formula can be entered into a cell. Example: MS Excel

When do you think spreadsheet might be used?

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2. Data Management – supports storage, retrieval, and manipulation of related data. Example: MS Access

When do you think data management might be used?

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3. Word Processing – this allows the user to manipulate text rather than just numbers. Example: MS WORD

When do you think word processing might be used?

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4. Desktop Publishing – represents a level of sophistication beyond regular word processing. This has been especially used in helping small businesses create high-quality advertising and marketing materials at reasonable costs. Examples: Corel Draw and Adobe Photoshop

Why does it represent a level of sophistication beyond regular word processing?

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5. Graphics – allows the user to create, store, and display or print charts, graphs, maps, and drawings. Examples: Autocad and Microsoft Paint

What are the processes or skills involved when an individual uses a graphics software?

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6. Multimedia – combines at least two media for input or output of data. Examples: MS PowerPoint, Macromedia Flash, and Swish

What kind of media is included in this software?

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7. Communications – allows computers to exchange data over cable lines or satellite whether individuals are located close together or far apart. Example: Internet

What is the objective of communications software?

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8. Speech Recognition Software – this controls the personal computers to accept instructions from voices. Example: Via Voice from IBM

Can you think of advantages and disadvantages of this software?

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9. Groupware – facilitates communication, coordination, and collaboration among people. It is important because it allows work groups – people who need to interact with one another within an organization – to communicate and share information, even when they are working together at a distance. Examples: IBM’s Lotus Notes/Domino, Net Meeting, and MS Exchange

What might be some benefits organizations get from this software?

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computer hardware

Computer, machine that performs tasks, such as calculations or electronic communication, under the control of a set of instructions called a program. Programs usually reside within the computer and are retrieved and processed by the computer’s electronics. The program results are stored or routed to output devices, such as video display monitors or printers. Computers perform a wide variety of activities reliably, accurately, and quickly.

It is an electronic machine that can accept, store, manipulate, and retrieve data and information.
PARTS OF A COMPUTER SYSTEM: hardware, software, and peopleware.

Computer hardware consists of the components that can be physically handled. The function of these components is typically divided into: CPU, input technologies, output technologies, memory, and communications technology.

CPU
CPUs contain processing units that interpret and implement software instructions, perform calculations and comparisons, make logical decisions (determining if a statement is true or false based on the rules of Boolean algebra), temporarily store information for use by another of the CPU’s processing units, keep track of the current step in the execution of the program, and allow the CPU to communicate with the rest of the computer.

A CPU is similar to a calculator, only much more powerful. The main function of the CPU is to perform arithmetic and logical operations on data taken from memory or on information entered through some device, such as a keyboard, scanner, or joystick. The CPU is controlled by a list of software instructions, called a computer program.

It consists of: Arithmetic/Logic Unit (ALU) - which performs calculations and comparisons. It performs specific operations such as addition, multiplication, and conditional tests.
Control Unit – which controls other hardware functions
Registers - store data and keep track of operations
Internal bus - connects the units of the CPU with each other and with external components of the system

INPUT TECHNOLOGIES
These are devices that permit the computer user to communicate with the computer.

HUMAN DATA ENTRY DEVICES Needs data entered by a user. These devices allow people to communicate with the computer.

Keyboard - keypad device with buttons or keys that a user presses to enter data characters and commands into a computer. Keyboards emerged from the combination of typewriter and computer-terminal technology.

Patterned from the typewriter’s QWERTY which was invented by American typewriter inventor and printer, Christopher Sholes in the 1890’s. The computer keyboard can be attached to the system unit through cable or by infrared transmitter.

Mouse - a pointing device that helps a user navigate through a graphical computer interface. Connected to the computer by a cable, it is generally mapped so that an on-screen cursor may be controlled by moving the mouse across a flat surface. Two common types of mouse, the Microsoft mouse (bottom) and the Apple ADB (Apple Desktop Bus) mouse (top).

It is popularized by Apple Macintosh.

Light pen - a stylus with a light sensitive tip that is used to draw directly on a computer's video screen or to select information on the screen by pressing a clip in the light pen or by pressing the light pen against the surface of the screen. The pen contains light sensors that identify which portion of the screen it is passed over.

The light pen doesn't require a special screen or screen coating, as does a touch screen, but its disadvantage is that holding the pen up for an extended length of time is tiring to the user.

Joystick - a pointing device composed of a lever that moves in multiple directions to navigate a cursor or other graphical object on a computer screen.

Trackball - basically an inverted mouse; the user rotates the ball itself while clicking nearby buttons. Trackball users argue the device is more efficient because it is stationary and saves arm movement; however, many mouse users are uncomfortable with the different style of input.

SOURCE DATA AUTOMATION
Objective: to input data with minimal human intervention. These technologies speed up data collection, reduce errors, and can gather data at the source of a transaction or other event.

Cash Transaction Devices – devices that are common in association with cash transactions.

1. Automated Teller Machine (ATM) - interactive input/output devices that enable people to make bank transactions from remote locations.
2. Point-of-sale (POS) – computerized cash registers that also can incorporate touch screen technology and bar code scanners. Allow the input of numerous data.
Optical Scanners
1. Bar Code Scanners – scans the black and white bar code lines
2. Optical Mark Reader – can detect the presence of pencil marks
3. Magnetic Character Reader – used in banking industry
4. Optical Character Recognition Software – scans to convert text into digital form
Sensors
Cameras
Voice Recognition Systems


OUTPUT TECHNOLOGIES
External devices that transfer information from the computer's CPU to the computer user.

Monitor or video display screen – used with most computers that display input as well as output. It uses cathode ray tube (CRT) technology to shoot beams of electrons to the screen.
Printers - take text and image from a computer and print them on paper.



MEMORY
Stores data for use by a computer

PRIMARY MEMORY A.k.a Main Memory Stores for very brief periods of time three types of information:
1. data to be processed by the CPU
2. instructions for the CPU as to how to process the data
3. operating system programs that manage various aspects of the computer’s operation

RAM Stands for Random Access Memory. A memory that can be read and written by the microprocessor or any hardware device.

Stores more information than the registers.

When you start most software programs on your computer, the entire program is brought from secondary storage into RAM. As you use the program, small parts of the program’s instructions and data are sent into the registers and then to the CPU.
ROM Stands for Read Only Memory. A memory that contains instructions or data that can be read but cannot be modified.

Non-volatile memory since critical instructions is safeguarded. ROM retains these instructions when the power to the computer is turned off.
CACHE MEMORY Consists of a small, high-speed memory system that holds recently used values. When the CPU makes a request to fetch or store a memory value, the CPU sends the request to the cache. If the item is already present in the cache, the cache can honor the request quickly because the cache operates at higher speed than main memory.

SECONDARY MEMORY Designed to store very large amounts of data for extended periods of time. Can have memory capacity or a gigabyte or more.
HARD DISK Made of a rigid metal, with the read-write head flying just above its surface on a cushion of air to prevent wear.

FLOPPY DISKS - made of flexible plastic with small pieces of a magnetic material imbedded in its surface. The read-write head touches the surface of the disk as it scans the floppy


CD-ROMS - high quality capacity, low cost, and high durability.
MAGNETIC TAPES Used primarily for backup storage. The surface of tape is coated with a material that can be magnetized. As the tape passes over an electromagnet, individual bits are magnetically encoded. Computer systems using magnetic tape storage devices employ machinery similar to that used with analog tape: open-reel tapes, cassette tapes, and helical-scan tapes (similar to video tape).

FLASH DISKS Holds more data than CD-ROMS and floppy. It can hold data as large as hard disks can, depending on its capacity.

history of computers

Throughout time, humans have invented ingenious calculating machines. One of the earliest was the abacus. It's about 5,000 years old. Mechanical calculators that could add and multiply (but not subtract!) were invented in the 1600s. In 1820, Charles Xavier Thomas de Colman invented the arithometer, a machine that could add, subtract, multiply and divide. It was Charles Babbage though, in the early 1800s, who designed mechanical calculating machines (see photo) that were the true ancestor of today's computers. Ada Byron King (Countess of Lovelace) was his programmer and today is considered the mother of computer programming.Babbage's design for his ultimate calculator, the Analytical Engine, was never produced. It did anticipate the four components essential to modern computing. These components are input, storage, processing and output.The problem with Babbage's and other mechanical calculators was just that—they were mechanical. The moving parts they relied on were slow and subject to breakdown.What made modern computers possible was the invention of something that could do calculations and other information processing with no moving parts and do it very fast. That something was electronic components. With electronic components, a fast and efficient machine such as Babbage proposed could be built with all four components essential to modern computing.



FIRST GENERATION COMPUTERS



1951 – 1958
Used vacuum tubes
Computers big and clumsy
Electricity consumption high
Electric failure occurred regularly - computers not very reliable
Large air conditioners was necessary because the computers generated heat
Programming in machine language
UNIVAC (1951)

Eckert and Mauchly completed the first commercial computer in the USA – the UNIVAC (Universal Automatic Computer). It consisted of a group of related machines which would put the client in a position to set-up an information system according to their needs. One could choose between high speed printers, magnetic drives (external memory), card to tape switches, and tape to card switches, high speed tape copiers and other equipment. It was a real all-purpose computer capable of numeric and alphanumeric calculations. It could print statements, sort accounts, predict the result of an election, and solve other mathematical problems.

SAGE - Semi Automatic Ground Environment was developed. (1951)
A computerised defense network was necessary for America. Large parts of Canada and America had no radar stations or control stations to monitor air traffic. Also, existing radar stations were only effective if there were few attackers who did not fly very fast or very low. MIT was asked to develop a network of radar stations. Computer monitors were developed to display the routes of aircraft and to accomplish direct communication with Whirlwind. Programs were written to enable Whirlwind to follow aircraft and to calculate new flight paths automatically. IBM was asked to build the SAGE computers and became leaders in real-time applications. SAGE was a 32-bit computer and used the technology of Whirlwind. They were the first computers to make use of backup computers and fault-tolerant systems. Every computer made use of two central processors, control units and read-write memory. The same input-output units and secondary memory was used. If one processor breaks, the second would take over automatically. A technique was also developed to trace weak tubes before they could burn out. SAGE computers were therefore very reliable.

EDVAC (Electronic Discreet Variable Computer) (1952)
The EDVAC (Electronic Discreet Variable Computer) was completed after the idea was thought of in 1945. John Von Neumann wrote the first manuscript that formulated the ideas of Eckert, Mauchly, the EDVAC engineers and himself. The computer was designed with a central control unit which would calculate and output all mathematical and logical problems and a memory which could be written to and read. (RAM in modern terms) which would store programs and data. He encouraged the use of binary numbers and Boolean algebra. A disagreement over the patent of the EDVAC delayed the development of the machine and gave Britain the opportunity to develop the first stored program computer.

IBM 701 (1953)
IBM markets the first IBM 701, a binary computer developed in accordance with Von Neumann’s ideas. It had 400 tubes, a read-write electrostatic memory of 4096 36-bit words and could multiply two words in 456 microseconds. The machine was manufactured in sections and packed in pieces so that each part could be transported in lifts and carried through standard size doorways. Through this, IBM became part of the computer market.

WHIRLWIND(1953)
The Whirlwind is equipped with magnetic core memory. It doubled the computers processing speed, data can be input four times faster, maintenance on the memory bank was decreased from 4 hours a day to two hours a week.
The Whirlwind was the source of many technological advances. It was the first real-time (can react immediately on an order or inquiry from a user) and contributed to the development of computer applications such as air traffic control, real-time simulations, industrial process control, ticket booking systems and banking systems. It lead to the development of multiprocessing where different programs are processed simultaneously by different parts of the machine and computer networks - the connecting of computers and other equipment to function as one system. It was the first 16-bit computer that made the development of mini-computers in the 1960’s possible.




SECOND GENERATION COMPUTERS



1958 – 1965
Transistor replaces vacuum tube
Computers become smaller
Generate less heat
Electricity consumption lower
More reliable
Faster
Core memory developed
Magnetic tapes and disks used
First operating systems developed
Programming in machine language as well as assembly language

Transistors in computers (1957 – 1958)
UNIVAC and the Philco Corporation introduce the first computers that use transistors in place of vacuum tubes. These new generation computers were an improvement in all areas over computers that used vacuum tubes. They were smaller, faster, more reliable and economical and much more powerful.
Integrated circuits (1961)
The first integrated circuits or microchips are commercially available. An integrated circuit is a small chip (usually made of silicon) comprising of a network of electronic circuits made up of transistors and other components.

Mini-computer: PDP-8 (1963)
Digital introduces the first successful minicomputer – the PDP-8. It was about as large as a fridge and used transistors and magnetic core memory. It could only execute one program at a time, data is executed by means of 12-bit words (as opposed to the mainframe computers 32-bit words) and had a 4Kb memory. It was genuinely cheaper than a mainframe computer. More people could now afford their own computer. Scientists and engineers used PDP-8's. The navy installed them in submarines, factories used them for machine control and banks used them for processing of accounts. The usability and cost effectiveness of the PDP-8 contributed to distributed-processing.

Real-time reservation system (1964)
IBM developed a real-time computerised ticket reservation system for American Airways. It was smaller than SAGE and was called SABRE (Semi-Automatic Business-Related Environment). It consisted of a duplex-computer and 1200 consoles linked to the control centre by means of telephone lines.
Real time processing: Data is updated when the transaction takes place.


IBM’s System 360 (1964)
IBM introduced the System 360. It consisted of 6 processors and 40 peripheral units. More than 100 computers per month were ordered. Companies bought places on IBM’s waiting list from other manufacturers. Other companies manufactured peripheral units that were compatible to IBM-equipment. IBM’s idea was to develop a family of computers whereby just the processor could be changed to a larger, faster unit. The peripherals and software had to be compatible with all processors.

THIRD GENERATION COMPUTERS

1965 – 1970
Integrated circuits developed
Computers smaller, faster and more reliable
Power consumption lower
High-level languages appeared

Gordon Moore (1965)
The semi-conductor pioneer, Gordon Moore (founder of Intel), predicted that the number of transistors that occurred on a microchip would double every year. It became known as Moore’s Law and is still valid today. In 1964 a chip of 2,5 mm2 had ten components. In 1970, one thousand components could fit onto the same sized chip.

1966
The first computers to use integrated circuits were manufactured. Burroughs used integrated circuits in parts of two computers - the B2500 and the B3500. Control Data and NCR made two computers using only integrated circuits - the CDC 7600 and the Century series respectively.

Intel (1968)
Intel was founded (INTegrated Electronics). They developed more sophisticated memory chips.
Magnetic core memory (1968)
Magnetic Core Memory was replaced by a microchip. The first 256 bit RAM microchips, and later the first 1Kb RAM (1024 byte) chips, caused the disappearance of Magnetic Core Memory that was used since the mid 1950's.

IBM System/370 (1969)
IBM replaced their System/360 with the System/370 that only used integrated circuits.

FOURTH GENERATION COMPUTERS

AFTER 1970
Integrated circuits, smaller and faster
Micro computer series such as IBM and APPLE developed
Portable computers developed
Great development in data communication
Different types of secondary memory with high storage capacity and fast access developed
Microprocessor (1971)
Intel developed the first microprocessor - a CPU on a microchip. It was called the 4004 and consisted of 2 250 transistors capable of processing 4 bits at a rate of 60 000 transactions per second. It could not be used as the CPU of a mini computer but was suitable for use in pocket calculators and in smaller electrical appliances. Packaged with other chips such as 2Kb ROM and 20 bit RAM, and mounted on a circuit board, the chip could execute any program that Intel engineers placed in the ROM. The 4004 could therefore be programmed to do far more than a basic pocket calculator.
1972
8008 Intel released the 8008 - an 8 bit processor powerful enough to be used as the CPU of a minicomputer. There were, however, many technical problems with the 8008.


8080 Microprocessor (1974)

The 8080 microprocessor was released - it made the development of the microcomputer possible.

MARK-8 (1974)
Johnathan Titus (a chemist with an interest in electronics) ordered an 8008 processor from Intel. He built a computer with 6 circuit boards which had 256 bytes RAM. The RAM could be expanded to 16 Kb but the machine had no ROM because Intel would have charged too much to manufacture it.
Each instruction had to be entered by means of switches. One byte at a time could be entered by manipulating a set of switches. A panel of lights produced the output of results. In July 1974, Titus published an article in Radio- Electronics in which he announced the MARK-8 to the world and offered the circuit boards and a set of assembly instructions for sale. The other components could be bought from Intel. Nearly 2000 MARK-8's were assembled. MARK-8 Computer Clubs were founded and some enthusiasts built their own peripherals, such as punched tape readers that made programming easier.
Although the MARK-8 was mainly used by electronics enthusiasts, it did prove that there was a very real demand for smaller, personal computers.

Motorola’s 6800 processor (1974)
Motorola developed a processor - the 6800 - which could perform all the functions of the 8080. It had similar abilities, but used different instructions to execute the same functions. then program compatibility problems started. Programs written for the 6800, would not work on the 8080 and vice-versa. The processor therefore determined the software that could be used on a computer.

1975 - January
Altair
Popular Mechanics published an article which announced the development of a true personal computer - the Altair 8800. This was developed by MITS (Micro Instrumentation and Telemetry Systems) in Albuquerque, New Mexico. It used the 8-bit Intel 8080 microprocessor and was made available in a complete kit, including all components and assembly instructions. 256 bytes of RAM was available. 16 slots were left open to include more RAM when necessary. Thousands of orders were received.
The Altair could be programmed by entering the machine code, one bit at a time, through the toggling of switches. One of the first programs written for the Altair was a game in which lights flashed in a specific pattern on the front panel. The user had to repeat the pattern, which grew increasingly complex as the game progressed.

Apple (1975)
Steve Wozniak and Steve Jobs founded the Apple Company. They built a microcomputer motherboard that used a 8-bit processor. The motherboard was a single circuit board and held 4 Kb RAM. It was not as powerful as the Altair, but it was cheaper and less complicated. It contained circuitry that allowed it to be connected to a monitor. Only people who knew their way around electronics, could operate this computer, but it still was a great success.
MOS 6502 processor (1976)
MOS technologies (a manufacturer of microchips) announced the development of the 6502 processor. It was an 8-bit processor with very few registers and a 16-bit address bus. It was used by Wozniak in the design of the Apple II and also in other popular computers such as the Commodore PET, Commodore 64 and the Atari. It facilitated the programming of graphics and also executed graphics faster than other processors available at the time. After it's release, the development of computer games proceeded rapidly.
Apple II (1977)
Wozniak and Jobs released the Apple II. It was cheap, had 16 Kb RAM and was ideal for playing video games. It was sold with a keyboard, a power supply and included 8 slots for peripherals. It could therefore be used with a wider variety of peripherals and programs.

Intel’s 8086 processor (1978)
Intel manufactured the 8086 processor that contained 16-bit registers and used segmented memory addressing. All x86 processors had to be compatible with the set of instructions, first used in this processor.

Motorola’s 68000 processor (1979)
Motorola released the 68000 which was used in the Apple Lisa and Macintosh computers.
IBM PC (1981)
IBM announced it's first Personal Computer - the IBM PC - an Intel 8088 processor containing 16-bit registers and 8-bit busses to power the machine. Only 64Kb RAM was available and this was soldered onto the motherboard. No expansion of memory was possible. It was distributed with a monochrome monitor and originally 2 floppy drives. 35 000 PC's were sold in 1981 and in 1993 the figure rose to 800 000. Other PC compatible computers were developed. Some firms supplied programs and peripherals that could be used with the IBM PC. The PC became widely accepted.

Intel’s 286 processor (1982)
Intel announced the 80286 microprocessor. This was used in the IBM PC AT (Advanced Technology). It operated at rates ranging from 8 - 20 MHz and was up to 6 times faster than the 4.77 MHz PC. It could also address up to 16Mb of RAM.

Apple’s Lisa (1983)
Apple announced the Lisa, a computer that used a mouse to move a cursor on the screen in order to select commands. The Lisa was the first commercial computer to use a Graphical User Interface (GUI). Commands were not typed in on the keyboard but selected from a series of menus or pictures (icons). The Lisa was not a great success. It was quickly followed by the more economical and easier to use Macintosh, that also used the GUI, and was a commercial success.
Programs had to be written specifically for the Macintosh. Microsoft also developed programs for this platform.

IBM PC XT (1983)
IBM announced the PC XT (eXtended Technology). Memory could be expanded to 640 Kb and it featured:
· 4,77 MHz processor speed
· Double floppy disks
· MS DOS version 3.3
· Later versions also had 10 or 20 Mb hard disk drives available.



IBM PC AT (1984)
IBM manufactured the IBM PC/AT (Advanced Technology). It used the Intel 80286 processor and featured:
· 16-bit registers and 24-bit address busses
· 12, 16 and 20 Mhz processor speed
· 1 Mb primary memory
· 40 Mb hard disk drive
· DOS 3.2 and higher.

FIFTH GENERATION COMPUTERS


Current and Future

The transition from one computer generation to the next takes years. It is also very difficult to be precise about the end of one generation and the beginning of the next generation. Although fourth-generation computers generally are used in the 1990's, some computers and computer systems have some properties of computers which are considered to be of the fifth-generation.
The most noticeable characteristic of fifth-generation computers is the ability to apply previously gained knowledge, draw conclusions and then execute a task. The computer will, in short, simulate the human ability to reason.
Computers will have to be able to classify information, search large databases rapidly, plan, and apply the rules which humans regard as clear thinking, make decisions and learn from their mistakes. Input devices for fifth-generation computers could also include speech and visual recognition.

Applications for fifth-generation computers
· Intelligent robots that could ‘see’ their environment (visual input - e.g. a video camera) and could be programmed to carry out certain tasks without step-by-step instructions. The robot should be able to decide for itself how the task should be accomplished, based on the observations it made of its environment.
· Intelligent systems that could control the route of a missile and defence-systems that could fend off attacks.
· Word processors that could be controlled by means of speech recognition.
· Programs that could translate documents from one language to another.
Some technological developments that could make the development of fifth-generation computers possible, include:
· Parallel-processing - many processors are grouped to function as one large group processor.
· Superconductors - a superconductor is a conductor through which electricity can travel without any resistance resulting in faster transfer of information between the components of a computer.

Today's computers already display some of the characteristics of fifth-generation computers.
Expert Systems helps doctors to reach a diagnosis by following the logical steps of problem solving just as if the doctor would have done it himself.
Speech recognition systems, capable of recognising dictation and entering the text into a word processor, are already available.