Overview
This lecture covers the fundamental components of computer hardware, the relationship between hardware and software, and explains the differences between main memory, secondary storage, RAM, and ROM.
Computer Hardware Components
- Hardware and software must be compatible for efficient system performance.
- Main hardware components include the CPU, memory, buses, and input/output (I/O) devices.
- The CPU (central processing unit) is the “brain” of the computer, executing program instructions.
- Multi-core processors perform more tasks simultaneously; cores can range from 2 (dual-core) up to 10 (as in the MacBook M1 Pro).
- Clock speed, measured in GHz, indicates how many cycles a processor executes per second.
- Buses are electronic pathways that transfer data and instructions between components; bus speed affects overall computer performance.
- Input/output devices (I/O) like the mouse, keyboard, and screen allow users to interact with the computer.
Memory & Storage
- Main memory provides fast, temporary storage for program instructions and data; measured in gigabytes (GB).
- RAM (Random Access Memory) is where active programs and data are stored for quick CPU access.
- Two main types of RAM: SRAM (used for cache, faster, non-replaceable) and DRAM (cheaper, slower, commonly used for system memory).
- ROM (Read-Only Memory) is pre-recorded memory used to boot the computer; retains data when powered off.
- Types of ROM:
- PROM (programmable once),
- EPROM (can be rewritten using UV light),
- EEPROM (can be rewritten electrically, no special equipment required).
- RAM is much faster and has higher capacity than ROM but loses data when the computer is turned off.
- ROM is more permanent, storing essential instructions (like boot programs).
- Secondary storage (e.g., hard drives, USB drives, cloud storage) holds data more permanently than main memory and offers greater capacity and data retention.
Key Terms & Definitions
- CPU (Central Processing Unit) — Executes instructions and processes data in the computer.
- Core — An individual processing unit within a multi-core processor.
- Clock Speed — Frequency of CPU operations, measured in GHz.
- Bus — Pathways that transfer data between hardware components.
- I/O Devices — Hardware for user interaction and data entry/output.
- RAM (Random Access Memory) — Volatile memory for active data and programs.
- SRAM/DRAM — Types of RAM; SRAM is faster, DRAM is cheaper and slower.
- ROM (Read-Only Memory) — Non-volatile memory for permanent instructions.
- PROM/EPROM/EEPROM — Types of ROM with varying programmability and rewrite capabilities.
- Secondary Storage — Devices for long-term data storage (e.g., HDDs, USB, cloud).
Action Items / Next Steps
- Watch the provided YouTube video on RAM and ROM in the Canvas course section.