Design For Accessibility: Getting it right from the start
Introduction to Computer Applications
1.
2. Computer System Component
Computer: A programmable electronic device
that can store, retrieve, and process data.
The word “Computer” emerged during WWII,
people who operated desk calculators were
called: Computers.
3. History of the Modern
Computer
Human: Could add a two 10 digit number in 10 seconds, with
Calculator, in 4 Seconds.
Mark 1: Also called “Harvard Mark 1” Could add two 10-
digit numbers in about 0.3 seconds. 30 times faster than
Pencil and paper.
ENIAC: Electronic Numerical Integrator and Computer. The
world's first electronic digital computer was developed by
Army Ordnance to compute World War II ballistic firing
Tables. Could add the same in 0.0002 seconds, 50,000 times
faster than a human, and 1,500 times faster than the Mark 1.
4. General Vocabulary
and Units
Bit: "Binary digIT" Computers happen to operate using the
base-2 number system, also known as the binary number
system ( 0, 1)
Byte: 8-bit collections (single, double precision)
Digital: Send – Receive 0’s and 1’s
Analog: AM - FM
Hertz: Unit of Frequency
Kilo-Hertz: 1000 Cycles
Mega-Hertz: 1 million Cycles
Giga-Hertz: 1 Billion Cycles
5. Components of a
Computer System
Computer
Hardware Software
Motherboard Operating System
Floppy Office 2003
Hard Drive Internet Explorer
8. Types of Computer
The word "minicomputer" (colloquially,
"mini") is a term for a class of smaller
computers that evolved in the mid-1960s and
sold for much less than mainframe and mid-
size computers from IBM and its direct
competitor. the term "minicomputer" came
to mean a machine that lies in the middle
range of the computing spectrum, in
between the smallest mainframe
computers and the microcomputers.
A data processing system employed mainly in
large organizations for various applications,
including bulk data processing, process
control, industry and consumer statistics,
enterprise resource planning, and financial
transaction processing.
Mainframes use proprietary operating
systems, most of which are based on Unix,
and a growing number on Linux. Over the
years they have evolved from being room-
sized to networked configurations of
workstations and servers that are an
extremely competitive and cost effective
platforms for e-commerce development and
hosting. Mainframes are so called because the
earliest ones were housed in large metal
frames.
A supercomputer is a computer at the
frontline of current processing capacity,
particularly speed of calculation. Introduced in
1960
These computers were used for complex
calculations such as forecasting weather and
quantum physics. Today, supercomputers are
one of a kind; they are fast and very
advanced. The term supercomputer is always
evolving as tomorrow's normal computers are
today's supercomputer.
A microcomputer is a
complete computer on a smaller
scale and is generally a synonym
for the more common
term, personal computer or PC
12. Memory
SRAM: Static RAM
Random Access Memory
DRAM: Dynamic RAM
EPROM: Erasable Programmable ROM
PROM: Programmable ROM
Read Only Memory
1 MB
2 MB
4 MB
8 MB
16 MB
32 MB
64 MB
128 MB
256 MB
512 MB
1024 MB
Extra Points: What mathematical equation
describes the pattern?
Memory Size in MB
13. Monitors
Output device,
Soft-Copy Output
Resolution is given by the amount of “Pixels”
Two categories: CRT (Cathode Ray Tubes)
and LCD (Liquid Crystal Display)
14. Printers
Output Devices
Hard Copy Output
Resolution is given in “dsi”. Dots per Inch.
Two Categories: Laser (B&W, Color) uses
Toner. Inkjet (Color) uses ink cartridges.
15. Types of Software and Their
Uses
Operating System Software (OS): Tell the
computer how to work and what to do.
Windows, Linux and Macintosh.
Driver: Software that tells a hardware
component how to work.
Application Software: Accomplish a task
Using a computer. Word, Excel, PowerPoint
A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation. Introduced in 1960
These computers were used for complex calculations such as forecasting weather and quantum physics. Today, supercomputers are one of a kind; they are fast and very advanced. The term supercomputer is always evolving as tomorrow's normal computers are today's supercomputer.