2. Computing History
● ENIAC (Electrical Numerical Integrator and Computer)
– Developed in 1946 by John W. Mauchly and J. Presper Eckert
● UNIVAC I
– First widely marketed universal automatic computer
– First UNIVAC I was sold to Census Bureau in 1951
– GE was the first commercial business to purchase UNIVAC I
●
IBM System 360 Line of Computers
– Revolutionized computer industry in 1960
– This was the first that could perform multiple tasks from multiple users.
3. Computing History
● Minicomputers
– Early 1970
– Minicomputers called minis, was a midrange computers, fitting within larger
mainframes and smaller micros.
● Microcomputer
– Late 1970
● IBM Personal Computer (PC)
– It is now used, along with microcomputer to describe the small, relatively
inexpensive and powerful small computer used for both business and
personal use.
– Used by one person or by a few people in the same area
4. Computer Sizes
● Mainframes
– Large
– Centrally located
– Used by large organizations
● Minicomputers
– Mid-sized
● Microcomputers
– Made possible by microprocessor
5. Literacy
● Computer Literacy
– Ability to use computing resources
● Information Literacy
– Understanding how and why information affects the
decision-making process
7. Processor
– The processor is the main unit where the processing is
performed. It is also called the CPU (Central
Processing Unit) or the computer processor or the
system unit.
– Processors control the calculations and logical
comparisons of data. They also direct and control the
movement of data from one location to another.
8. 2 Characteristics of Processor
● Processor Speed
– It measures the numbers of cycle that occur per second.
● Word Size
– Bit is a single value of zero or one. Word is the measure
of how many bits may be moved with one cycle of the
processor. A string of eight bits together make one byte,
and one byte is enough bits to represent a character.
9. Memory
● Material is stored in a computer in two ways:
1. Memory – also called main memory, primary memory or
random access memory (RAM), refers to the storage area
where both data being processed and the program instructions
being executed.
2. Storage – also called secondary storage. It is a memory on a
storage device that is separated from the processor’s circuit
board. Storage takes the form of magnetized coding on the
surface of the storage device.
10. Conversion from Bits to Bytes and
Further
1 bit
8 bits
1,024 bytes
1,048,576 bytes
1,099,511,627,776 bytes
1,124,899,906,842,624 bytes
= a single value of 0 or 1
= 1 byte = 1 character
= 1 kilobyte (1 KB)
= 1 megabytes (1 MB)
= 1 terabyte (1 TB)
= 1 petebyte (1 PB)
11. Brief Definition of Different Memory
Types
TYPE DEFINITION
RAM Random Access Memory, computer programs and data are
loaded into RAM to be executed by the computer processor.
ROM Read-Only Memory, holds information used by the operating
system and processor when the computer is started.
DRAM Dynamic RAM, allows buffering of data and increases
efficiency of RAM.
SDRAM Synchronous DRAM, runs much faster than most conventional
memory because it synchronizes its cycles with the processor’s
cycles.
SIMM Single In-line Memory Module, holds 9 memory chips and
transmits 32 bits of data per cycle
DIMM Dual In-line Memory Module, transmits 64 bits per data cycle
12. Storage
● Storage media usually take the form of tape or
disk. The computer hardware that reads from and
writes to the medium is a drive. A motor inside
the computer hardware drives the medium
forward so that data can be read from and written
to different locations.
13. Sequential Vs. Random Access
Storage
Sequential Access Storage keeps data in format. Sequential devices such as
computer tapes are like cassette tapes. To listen to the third song you have to
listen to the first and second songs. Computer disks that you used with a
microcomputer are random access storage media. Random access storage
was expensive compared to sequential storage devices during the early days
of computing. Today, the cost of random access storage is small that it is the
most commonly used storage. If the data has been damaged or lost – there
will be enormous amount of data to be stored. It takes special effort and
advance skills to work with random access data.
14. Permanent Vs. Removable Storage
The fixed disk in microcomputers was composed of hard disk surfaces enclosed in a
metal case inside the microcomputer. Today’s microcomputer offers both fixed and
removable disk storage. Removable media are commonly called floppy media. The
storage devices were given names A,B,C and so forth to represent the first, second,
third storage device. The first microcomputers had a single removable disk storage
medium, the A drive as controlling the first removable storage medium, a second
removable disk was added and it was controlled by the B drive. Fixed storage media
came after microcomputers already had two removable media. The first fixed
storage was controlled by the C droves.
15. Removable Disk and their Storage
Capacities
3.5 inch floppy disks holds 1.44 MB of data
Zip disk may hold 100MB or 250MB of data
Jaz disk holds 2GB of data
CD disk holds 650MB of data
DVD disk holds 5GB to 20GB of data
16. Input Devices
● Human-Captured Data – it provides a direct
mechanism for the user to control the computer.
– Ex: Keyboard, microphone
● Machine-Captured Data – computer-captured data
is less costly. Most compiling reason for machine-
captured data are speed and accuracy in the data
capture process.
– Ex: Barcode
17. Output Devices
● Monitors
– The greatest advances in computer screens have been
color and size. Color added a dimension that makes
graphic image seems realistic. Size of the monitor
meant that more information could be presented on
the screen at one time.
● Screen resolution
– refers to the number of pixels, individual dots of light
on the monitors.
18. Output Devices
CGA (Color Graphics
Adapter)
The first move from the monochrome
monitor. It only allowed 16 colors.
EGA (Enhance Graphics
Adapter)
allowed 64 colors to be displayed on the
monitor.
VGA (Video Graphics
Adapter)
allows 256 simultaneous colors.
Its resolution is 640 x 480.
SVGA standard (Super VGA) allows even greater resolution and more
colors.
GUI (Graphical User
Interface)
depends upon a computer screen that can
show precise details in the icons as well as
color that make the icon easily recognizable.
19. Output Devices
● Printer
– The key characteristics of change are resolution for printing and the
speed of printing.
● Impact printers
– mechanical strike against the paper.
– Used either formed-type characters or series of wire pins that make
dots on the paper. Dots placed close together form the characters.
● Nonimpact printers
– Do not require a mechanical strike against the paper.
● Ex:
– Laser printers which are essentially copier machine
– ink-jet printers that spray ink onto the surface of the paper.
20. Multimedia
● It is the use of more than a single medium at a
time.
● Multimedia capabilities have been possible for
some time but the constraining factor was that
audios and images required more storage space
and processor power than the processing text.
21. Keep abreast hardware changes
● It is very difficult to keep abreast of hardware
changes. There are 2 things you should
remember.
1)Moore’s Law – power of computing hardware
compared to its price to double every 18
months.
2)You need to cultivate resources of new
information about computing resources
22. Software
Two basic types of software:
1)System Software performs fundamental tasks
that all users of a particular computer require.
2)Application Software processes user’s or firm’s
data
23. Software
Three basic types of System Software:
1) Operating System – it manages the computer processes, functioning as an interface connecting
the user, the software that processes the firm’s data and the hardware. There are several basic
functions that operating system can perform.
• Schedule Tasks
• Manage Hardware and Software Resources
• Maintain System Security
• Enable Multiple User Resources Sharing
• Handle Interrupts
2) Utility Programs – often called a utility, is a routine that enables the user to perform certain basic
data processing operations that are unique to a particular user’s applications.
3) Language Translators – programing languages that translate the programmer’s instructions into
those of the computer were developed to provide a more friendly way to instruct the computer.
• Fourth-Generation Languages (4GL) – is the one that expresses what is to be done by the computer
without explicitly defining how the tasks will take place.
24. Software
Two basic type of Application Software:
1) Prewritten Application Software – also called prewritten
application package and off-the-shelf application
software. To use it, the user need only install the software
on their hardware, with little modification. The software
allows the user to make small significant adjustments.
2 advantages:
● It is available now
● It is less expensive than custom software
25. Software
2)Custom Application Software – a the business
might have its own programmers or consulting
group of programmer to write the application
software to meet its needs. Such software is called
custom application software.
26. Rule of User-Friendly Software
● Businesses need programmers to create applications
– Employees
– Consultants
– Contracts with other companies
● Simple intuitive software is user-friendly
● Business users have expertise in their areas
– Need to work with technical experts
27. Keeping Abreast of Software Change
Software changes almost rapidly as hardware. Most
organizations assign responsibility for keeping abreast of
software changes to information systems professionals in
the organization. Information system professional are
routinely contacted concerning updates in the version or
features of application software already owned by the
organization. These changes are important but the most
important agent for software change must be the user in
meeting the needs of the organization.