Information Coding System

Check Digit

A simpler form of a checksum.

• Adds a single digit to the data.
• Efficient but has limitations in error detection.

Checksum

A value added to data, calculated using an algorithm.

• Detects errors but cannot correct them.
• Efficiency depends on the specific algorithm used.

Majority Voting

Each bit is transmitted multiple times to increase reliability.

• Detects and corrects errors based on the most common value received.
• Inefficient due to increased data size leading to higher bandwidth usage.

Parity Bit

A single bit added to data to facilitate error checking.

• Two types: Even parity (ensures an even number of 1s) and Odd parity (ensures an odd number of 1s).
• Cannot detect errors when an even number of bits are altered.

ASCII

Stands for American Standard Code for Information Interchange.

• Uses 7 bits to represent a total of 128 characters, which include:
• Uppercase letters (A-Z)
• Lowercase letters (a-z)
• Digits (0-9)
• Various symbols.

Unicode

A standard developed to represent a diverse range of alphabets and symbols.

• Uses 8 to 48 bits (1 to 6 bytes) per character.
• Supports languages like Arabic, Greek, Cyrillic, and more, facilitating internationalization.

Character Code

A numerical value assigned to a specific character.

• Example: A = 1, B = 2, etc.
• Can be converted to binary for computer processing.

Even Parity

A parity check method that ensures the total number of 1s in the data is even.

Odd Parity

A parity check method that ensures the total number of 1s in the data is odd.

Error Checking

The process of identifying errors that may occur during data transmission.

Error Correction

The process of fixing detected errors in the data without requiring retransmission.