Types of Computers | C Programming Lang

Types of Computers

1. Mainframe Computers
2. Mini Computers
3. Micro Computers
4. Super Computers

Mainframe Computers work at a high speed, and have a high storage capacity
Mini Computers are medium and powerful Computers.
Micro Computer are the commonly used as general purpose Computer

=> Data Storage in a Computer
1. 4bits = 1 Nibble
2. 8bits = 1 byte
3. 1024 bytes = 1k or 1kb (kilobyte)
4. 1024KB = 1MB (mega byte)
5. 1024MB = 1GB (Gega byte)
6. 1024GB = 1TBC Terabytes

=> Organization of Computer:
1. Arithmetic and Logical unit
2. Memory unit
3. Control unit
4. Input unit
5. Output unit
The Input and Output units are used to receive and display Inputs & Solutions Common i/p & o/p devices : Keyboard, mouse, monitor, printer

The CPU (Central Processing Unit) Consists of:
1. ALU (Arithmetic Logic Unit)
2. CU (Control Unit)
3. MU (Memory Unit)

1. The Control Unit Controls all the activities of the Computer. It sends commands and control signals and finds the sequence of instruction to be executed.
2. Memory Unit is the place where all input data and results are stored. Computer memory is also available in the form of Random Access Memory (RAM)
3. ALU Consists of CKTs for arithmetic operations(+,-,*,/) and logical operations (<,>,>=,<=,==,!=)

Connected components of CPU are called peripherals
Input devices       Output devices
1. Keyboard          1. Printer
2. Mouse              2. Monitor
3. Joystic              3. Dot Matrix Printer
                            4. Laser printers
                            5. LCD
Storage Devices :
1. Floppy disk
2. Hard disk
3. Compact disk

Computer Main Memory :
Primary memory    - RAM (Random Access memory)
Secondary memory  - ROM (Read only memory)
                  - Hard disk

RAM : It is a temporary storage medium in a computer. The data to be processed by the computer are transferred from a storage devices or a keyboard to RAM results from a executed program are also stored in RAM. The data stored will be erased when the computer is off.

ROM (Read only Memory) : This is a non-volatile or data storage medium which stores start up programs (operating systems). This essentially stores the BIOS (Basic Input Operating System)

Note : Basically Computer System components communicate it binaries as (0's & 1's, 0 refers OFF state,1 refer ON state)

Languages of different Generation Computer:
1. First – Generation Language : All the instructions are in the binary form and are referred to as machine level or low level language (LLL). It is very difficult to read the instructions written in binary
Eg : 00110101011101110001, 101100001010101

2. Second – Generation Language: all the instruction are in the forms of mnemonics.
The symbolic instruction language called as Assembly Language. All the symbolic instructions are converted into binaries with the help of translator called Assembles.
ASCII (American Standard Code For Information Interchange) is commonly used for translation of source Program into object program
Source Program    Eg : ADD A, B, R,
                       More R,S
Assembler              Translated by Assemble
Object Program         0101 10101010
                       0100 00001101

3. Third – Generation Language : These are written in English with symbols and digits.
Then are known as High level language (HLL). common high level languages are c,c++, COBOL, BASIC, FORTRAN, PASCAL, etc.
For execution the program is translation into binary form by compiler or interpreter.

4. Fourth – Generation Language (4GL?s) : is a programming language or programming environment designed with a specific purpose in mind, such as the development of commercial business software. In the history of computer science, the 4GL followed the 3GL in an upward trend toward higher abstraction and statement power. The 4GL was followed by efforts to define and use a 5GL.