Computer System Personnel Roles and Digital Numbering Bases

1.5 The Human Element in Computer Systems

The human element, or personnel, is the most important component within a computer system. It comprises a group of people who perform various functions related to the use and maintenance of computers and applications.

Key Roles in Computer System Personnel

• Staff Director: Responsible for directing and coordinating a department, a data processing center, or any related division.
• Staff Analysis (System Analyst): Manages application development, focusing on design, production of algorithms, and analyzing possible uses and modifications.
• Programming Personnel: In charge of transcribing the algorithms designed by the analyst into a specific programming language. This role also involves implementing the programs and conducting test kits.
• Staff Development and Operation: Deals with the implementation and ongoing operation of programs and applications.

1.6 Information Coding and Numbering Systems

Data Classification and Representation

Information and data types can be classified based on their role in processing:

1. Input Data: Data entered into the system (e.g., via keyboard).
2. Process: The manipulation of data.
3. Output Data: The results generated by the system.

Classification by Variability

• Fixed Data (Constants): Data that remains unchanged during processing.
• Variable Data: Data whose value can change during processing.

Classification by Type of Content

Depending on how they are used, data can be classified into:

• Numeric Data: Consists of digits (0–9).
• Letter Data: Consists of alphabetical characters (a–z).
• Alphanumeric Data: Consists of letters, numbers, and special characters.

Understanding Numbering Systems

Humans communicate, store, and use information primarily using the decimal system, especially for numeric data. However, since the computer uses digital circuits, it relies on the binary system. Therefore, we need to transform our data into binary format. Numbering systems are equivalent ways of representing quantities.

Numbering systems are defined by symbols (digits) that indicate a quantity based on the symbol itself and its position (positional systems). They are characterized by their base—the number of different symbols that can be utilized. Mathematical notation is often used to indicate the base of a specific quantity.

Common Numbering Systems in Computing

Decimal System (Base 10)

This is the positional system we currently use, utilizing 10 symbols (0 through 9).

Binary System (Base 2)

This system uses only two symbols: 0 and 1. It is the system used internally by the computer. Each of these numbers is called a bit, which is the smallest unit of information. Decimal symbols can be represented in binary using the fundamental theorem of numbering.

Octal System (Base 8)

This system uses symbols ranging from 0 to 7. It represents quantities positionally by powers of eight. Each symbol in base eight can be represented by a combination of three binary digits.

Hexadecimal System (Base 16)

This system uses 16 symbols. It uses digits 0 through 9, and then letters (A, B, C, D, E, F) to represent values 10 through 15. Each symbol in base 16 represents a combination of four binary digits.

Basic Binary Arithmetic Operations

Binary Addition Rules

0 + 0 = 0
0 + 1 = 1
1 + 0 = 1
1 + 1 = 0 (with a carry)

Binary Subtraction Rules

0 - 0 = 0
0 - 1 = X (Indeterminate without borrowing context)
1 - 0 = 1
1 - 1 = 0

Binary Multiplication Rules

0 * 0 = 0
0 * 1 = 0
1 * 0 = 0
1 * 1 = 1