Computer Systems

Introduction to Computer Systems

A Computer System is an electronic system that takes input, processes it according to given instructions, stores data, and produces output. In banking and financial institutions, computer systems are used for core banking, fund transfers, ATM operations, internet banking, mobile banking, MIS reporting, risk analysis, and data storage.

A computer system mainly consists of:

  • Hardware
  • Software
  • Data
  • Users
  • Procedures

These components work together to perform various operations efficiently and accurately.

Basic Components of a Computer System

A computer system is based on the IPO cycle:

Input → Process → Output

(A) Input Unit

The input unit is used to enter data and instructions into the computer. It converts user instructions into machine-readable form.

Common input devices:

  • Keyboard
  • Mouse
  • Scanner
  • Barcode reader
  • MICR (used in banks for cheque processing)
  • Biometric devices

In banking, cheque truncation systems (CTS) and biometric authentication are examples of input systems.

(B) Central Processing Unit (CPU)

The CPU is called the brain of the computer. It performs all calculations and logical operations.

It consists of three main parts:

Arithmetic Logic Unit (ALU)

Performs arithmetic operations (addition, subtraction, multiplication, division) and logical operations (AND, OR, NOT comparisons).

Control Unit (CU)

Directs all operations inside the computer. It controls input, output, and processing activities.

Registers

Small high-speed storage areas inside CPU used for temporary data storage.

In exam questions, remember:

  • ALU = Calculations
  • CU = Controls operations
  • Registers = Temporary storage

(C) Memory Unit

Memory stores data and instructions.

Memory is divided into:

Primary Memory (Main Memory)

Primary memory is directly accessible by CPU.

It includes:

  • RAM (Random Access Memory)
    • Volatile memory (data lost when power off)
    • Used for temporary storage
  • ROM (Read Only Memory)
    • Non-volatile
    • Stores permanent instructions
  • Cache Memory
    • Very fast memory
    • Located between CPU and RAM
    • Improves speed

For exam:
RAM = Temporary + Volatile
ROM = Permanent + Non-volatile

Secondary Memory (Auxiliary Storage)

Used for long-term data storage.

Examples:

  • Hard Disk
  • SSD
  • Pen Drive
  • CD/DVD
  • External Hard Drive

In banking, customer databases and transaction records are stored in secondary memory.

(D) Output Unit

The output unit displays processed results.

Common output devices:

  • Monitor
  • Printer
  • Speakers

In banks, account statements, transaction receipts, and reports are examples of output.

Types of Computers

Computers are classified based on size and purpose:

(1) Supercomputers

Used for complex scientific calculations like weather forecasting.

(2) Mainframe Computers

Used by large banks and organizations for processing huge volumes of transactions.

(3) Minicomputers

Medium-scale business operations.

(4) Microcomputers (Personal Computers)

Used in bank branches for daily operations.

For exam:
Large banks → Mainframe
Branch operations → Microcomputers

Hardware and Software

Hardware

Hardware refers to physical components of a computer system such as:

  • Monitor
  • Keyboard
  • CPU
  • Hard disk

It can be classified as:

  • Input devices
  • Output devices
  • Processing devices
  • Storage devices

Software

Software is a set of programs that instructs the computer what to do.

Software is divided into:

(A) System Software

Controls overall operations of computer.

Main example:

  • Operating System (Windows, Linux, Unix)

Functions:

  • Memory management
  • Process management
  • File system management
  • Device management

In banks, core banking software runs on operating systems.

(B) Application Software

Designed for specific tasks.

Examples in banking:

  • Core Banking Solution (CBS)
  • MS Excel
  • Tally
  • Internet Banking Software

(C) Utility Software

Helps maintain system performance.

Examples:

  • Antivirus
  • Disk cleanup
  • Backup software

Operating System (OS)

Operating System acts as an interface between user and hardware.

Functions of OS:

  • Process scheduling
  • Memory allocation
  • File management
  • Security management

Examples:

  • Windows
  • Linux
  • Unix

Banks generally use Unix/Linux-based systems for security and stability.

Data and Information

For exam, understand the difference:

  • Data = Raw facts (e.g., account number, transaction amount)
  • Information = Processed data (e.g., account statement, balance report)

Processing converts data into meaningful information.

Number System in Computer

Computers use binary system.

Main number systems:

  • Decimal (Base 10)
  • Binary (Base 2)
  • Octal (Base 8)
  • Hexadecimal (Base 16)

Binary digits are called bits (0 and 1).

Important terms:

  • 1 Bit = Binary digit
  • 4 Bits = Nibble
  • 8 Bits = 1 Byte
  • 1024 Bytes = 1 KB

Computer Processing Cycle

Computer follows a cycle:

  1. Input
  2. Processing
  3. Storage
  4. Output

Example in banking:
Customer enters withdrawal request → System verifies balance → Deducts amount → Updates account → Prints receipt.

Generations of Computers

Computers evolved in five generations:

  1. First Generation – Vacuum Tubes
  2. Second Generation – Transistors
  3. Third Generation – Integrated Circuits
  4. Fourth Generation – Microprocessors
  5. Fifth Generation – Artificial Intelligence

Modern banking systems use fourth and fifth generation technologies.

Applications of Computer Systems in Banking

Computer systems are very important in banking operations:

  • Core Banking Solution (CBS)
  • ATM network
  • NEFT, RTGS, IMPS
  • Internet banking
  • Mobile banking
  • Customer Relationship Management (CRM)
  • Risk management and data analytics

Without computer systems, modern banking cannot function efficiently.

Characteristics of Computer Systems

Important features:

  • High speed
  • Accuracy
  • Automation
  • Storage capacity
  • Reliability
  • Versatility

However, computers cannot think on their own. They work based on instructions.

Limitations of Computer Systems

  • No intelligence
  • No emotions
  • Dependent on electricity
  • GIGO principle (Garbage In, Garbage Out)

If wrong data is entered, output will also be wrong.

Conclusion

A computer system is an integrated system consisting of hardware, software, memory, CPU, and input-output devices. It works on the Input-Process-Output cycle and plays a crucial role in banking operations.