Micro Computers
Introduction
Computers are the electronic devices
that can follow instructions to accept input process that input and produce
information. From capability point of view there are four types of computers as
mentioned in the previous chapter.
1. Micro Computers
2. Mini Computers
3. Mainframe Computers
4. Super Computers
2. Mini Computers
3. Mainframe Computers
4. Super Computers
1. Micro Computers
The most widely used and fastest
growing type of computer is the micro computer. There are two categories of
micro computers desktop and portable. Desktop computers are small enough to fit
along the side of a desk and yet are too big to carry around. Personal computer
are the type of desktop. Portable computers are the micro computers that are
small enough and light enough to move from one place to another. There are four
categories of portable computers.
i. Laptops
ii. Notebooks
iii. Sub notebooks
iv. Personal Digital Assistants.
Components of Computer
The computer itself the hardware has many parts but each
fall into one of four categories.
1. Processor
2. Memory
3. Input and Output Devices
4. Storage Devices.
Only first two categories will be discussed in this chapter, whereas next two categories will be studied in the subsequent chapter.
1. Processor
2. Memory
3. Input and Output Devices
4. Storage Devices.
Only first two categories will be discussed in this chapter, whereas next two categories will be studied in the subsequent chapter.
The CPU or Processor
The part of the computer that runs the program (executes
processor) is known as the processor or central processing unit. The processor
is like the brain of the computer the part that organizes and carries out the
instructions that come from either user or software. The central processing
unit has two components the control unit and the arithmetic logic unit.
Control Unit
The Control unit tells the rest of the computer system how
to carry out a program’s instruction. It directs the movement of the electronic
signals between teh memory which temporarily holds data, instruction and
processed information and the arithmetic logic unit. It also direct the signal
between the CPU and the input and output devices.
Arithmetic-logic Unit
The arithmetic logic unit usually called ALU performs two
types of operations arithmetic and logical. The arithmetic operations are the
fundamental math operations addition, subtraction, multiplication and division.
Logical operations consists of comparisons. i.e. two pieces of data are
compared to see whether one is equal to (=), less than (<) or greater than
(>) the other.
Memory (RAM)
Computer has two types of memory random access memory
(RAM) and read only memory. (ROM) In this chapter only RAM will be studied
whereas ROM will be studied later. RAM also known as primary memory internal
memory or main memory hold.
Data for processing
Instruction for processing the data that is the program
Information that is processed data waiting to be output and sent to secondary storage such as floppy disk in a disk drive.
One of the most important fact to know about memory is that part of its content is held only temporarily. In other words, it is stored only as long as computer is turned on. When the machine is turned off the contents immediately vanish.
The next important facts of know about memory is that its capacity varies in different computers.
Data for processing
Instruction for processing the data that is the program
Information that is processed data waiting to be output and sent to secondary storage such as floppy disk in a disk drive.
One of the most important fact to know about memory is that part of its content is held only temporarily. In other words, it is stored only as long as computer is turned on. When the machine is turned off the contents immediately vanish.
The next important facts of know about memory is that its capacity varies in different computers.
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