Computer Memory and Magnetic Disks Overview

Magnetic Disks and Tapes

• Magnetic disks are circular plates made of metal or plastic, coated for data storage.
• Magnetic tapes are a recording medium with a thin magnetizable coating for data storage.

CPU Registers

• Registers are fast memory units within a CPU that aid in executing program operations.
• Functions of registers include:
  • Storing instructions for rapid access and execution.
  • Holding temporary results from calculations performed by the CPU.
  • Providing quick access to essential data for optimized performance.
• The CPU is often referred to as the brain of the computer system.

CPU Components

• ALU (Arithmetic Logic Unit) is responsible for performing arithmetic and logical functions.
• A & B registers hold the input data for processing.
• The accumulator receives and stores results from calculations.
• The instruction register contains the current instruction being executed.
• The instruction pointer directs the CPU on the next action to take after the current instruction.
• Cache memory is faster than RAM and temporarily stores frequently accessed data.
• MMU (Memory Management Unit) regulates data flow within the CPU.
• The CPU clock control unit ensures synchronization for efficient processing.
• RAM (Random Access Memory) stores programs and data for immediate access.

Addressing Mode

• Addressing mode determines how to calculate an effective memory address for operations.
• Key purposes include:
  • Enabling efficient execution of program literals.
  • Identifying the exact location of operands.
• Various types of addressing modes include:
  • Immediate: Operand is directly specified within the instruction.
  • Direct: Operand is indicated using assembly language or machine code.
  • Indirect: Operand data is accessed from memory.
  • Spatial: Addresses refer to specific locations in spatial memory.

Opcode and Operand

• OpCode (Operation Code) indicates the action the CPU must perform for an operation.
• Operand refers to the data or location specified within an instruction for processing.

Process Scheduler

• The process scheduler simulates how an operating system (OS) manages execution processes.
• It’s responsible for allocating CPU time to various tasks and processes.

Scheduler Algorithms

• First Come, First Served (FCFS): Processes are executed in the order they arrive in the ready queue.
• Shortest Job First (SJF): Prioritizes the execution of processes with the shortest burst time.
• Round-Robin (RR): Manages process execution in a fair and cyclic manner, allowing each process a time slice.

Explore the fundamentals of magnetic disks and their functioning as a magnetic recording medium. Learn about CPU registers, their purpose in storing instructions, holding temporary answers, and providing quick access to important data. This quiz covers essential concepts in computer memory.