ASCII / ISCII / UNICODE

-

    Internal storage of encoding characters
  A computer is capable of handling numeric data but in addition to numerical data, a          computer must be able to handle non-numerical information. In other words, a              computer should recognize codes that represent letters of the alphabet,                            punctuation and other special characters as well as numbers. These codes are            called alphanumeric codes.



1.     ASCII (American Standards Code for Information Interchange)
ASCII code is most widely used alphanumeric code used in computers. It is used extensively in small computers, peripherals, instruments and communication devices. ASCII-7 can represent 27=128 characters. ASCII-8 can represent 28=256 characters. It is an extended form ASCII-7. ASCII code is used for the transfer of alphanumeric information between a computer and I/O devices. A computer uses this code to internally store the information that an operator types in the computer’s keyboard.







2.    Extended ASCII Codes





3.     ISCII: (Indian Standard Code for Information Interchange)
A lot of efforts have gone into facilitating the use of Indian languages on computers. In 1991, the Bureau of Indian Standards adopted the ISCII. It is an 8-bit code which allows English and Indian Scripts alphabets to be used simultaneously. Characters coded in ISCII need 8 bits for each character. A special keyboard layout for entering ISCII called INSCRIPT was also specified and adopted.

4.    Unicode
Unicode is a new universal coding standard adopted by all new platforms. It is promoted by Unicode Consortium which is a non-profit organization. Unicode provides a unique number for every character irrespective of the platform, program and the language. It is a character coding system designed to support the worldwide interchange, processing, and display of the written texts of the diverse languages. The latest version contains a repertoire of 136,755 characters covering 139 modern and historic scripts.


Comments

Post a Comment

Popular posts from this blog

CISC / RISC / EPIC

-
Classification of Microprocessors 1.     CISC Processors: CISC is known as Complex Instruction Set Computer . The CISC approach attempts to minimize the number of instructions per program, sacrificing the number of cycles per instruction. Computers based on the CISC architecture are designed to decrease the memory cost . The number of instructions per program can be reduced by embedding the number of operations in a single instruction, thereby making the instructions more complex. For example, MUL(Multiply) . It performs operations such as load from memory, an arithmetic operation and a memory store all in single instruction. Example: IBM 370/168, Intel 80486 etc. Advantages: a.      Microprogramming is as easy as assembly language to implement and much less expensive than hardwiring a control circuit. b.      Fewer instructions are needed to implement a particular computing task, which led to lower memory...
Read more

Evolution of Computers

-
Image
Evolution of Computers The growth of computer industry started with the need for performing fast calculations. The manual method of computing was slow and prone to errors. So attempts were made to develop faster calculating devices. The journey that started from the first calculating device i.e. Abacus has led us today to extremely high speed calculating devices. Let us first have a look at some early calculating devices and then we will explore various generations of computer. Abacus Abacus was discovered by the Mesopotamia’s in around 3000 BC. An abacus consisted of beads on movable rods divided into two parts. (Fig-1) Addition and multiplication of numbers was done by using the place value of digits of the numbers and position of beads in an abacus. Fig. Abacus The Chinese further improved on the abacus so that calculations could be done more easily. Even today abacus is considered as an apt tool for young children to do calculations. In an abacus, each row is thought o...
Read more