(UHI) – Complete Lecture Notes 2025
🟦 1. Introduction to Computing
Definition
Computing is the study and use of computer systems to solve problems, process data,
and perform automated tasks efficiently.
Importance of Computing
• Automation → used in business, healthcare, and research.
• Communication → email, video calls, collaboration tools.
• Innovation → Artificial Intelligence (AI), Internet of Things (IoT), Big Data.
History of Computing (Timeline)
• 1940s: ENIAC – first programmable digital computer.
• 1950s–60s: Mainframes, transistor-based computers.
• 1970s–80s: Personal Computers (PCs).
• 1990s–2000s: Internet, laptops, mobile devices.
• 2000s–Present: Cloud computing, AI, smart devices.
Key Terms:
CPU, RAM, ROM, Storage, Input/Output, Algorithm, Software, Hardware.
🟦 2. Computer Systems & Architecture
Main Components:
• CPU (Central Processing Unit): Executes instructions.
• Memory:
, o RAM (volatile – temporary).
o ROM (non-volatile – permanent).
• Storage Devices: HDD, SSD, Optical Drives.
• Input/Output Devices: Keyboard, Mouse, Monitor, Printer.
• Motherboard & Buses: Connect all components.
Von Neumann Architecture
• One memory for both data & instructions.
• Cycle: Fetch → Decode → Execute
o Fetch instruction from memory.
o Decode in CPU.
o Execute operation.
Registers: Accumulator, Program Counter, Instruction Register.
Diagram (Text Form):
+----------------+
| Input Unit |
+----------------+
|
v
+----------------+
| CPU |--> Registers (PC, IR, ACC)
| ALU + Control |
+----------------+
|
v
+----------------+
| Memory |
+----------------+
|
v
+----------------+
| Output Unit |
+----------------+