COMP

• What does the cheat sheet cover for J277/01?


  Computer systems specification
• What is the main job of the CPU?

  To execute programs using the F-D-E cycle
• What does F-D-E stand for?

  Fetch-Decode-Execute
• What is the role of the program counter in the CPU?

  It stores the address of the next instruction
• How does the CPU execute a program step by step?

  Checks program counter, fetches, decodes, executes
• What does the ALU stand for?

  Arithmetic Logic Unit
• What is the function of the Control Unit (CU)?

  Fetches, decodes, and executes instructions
• What is cache in the CPU?

  High-speed memory for frequently used data
• How does cache improve CPU performance?

  Reduces time waiting for data from memory
• What are the levels of cache?

  L1, L2, and L3
• What is the difference between cache and registers?

  Cache is larger and stores frequently used data
• What does Von Neumann architecture state?

  Data and instructions are stored as binary
• How does the processor handle instructions in Von Neumann architecture?

  Fetches instructions one at a time in order
• What is the purpose of the program counter (PC)?

  Holds the memory address of the next instruction
• What does the Memory Address Register (MAR) do?

  Holds the address of the current instruction
• What does the Memory Data Register (MDR) hold?

  Contents found at the address in the MAR
• What is the function of the Current Instruction Register (CIR)?

  Holds the instruction currently being executed
• What does the Accumulator (ACC) do?

  Holds data being processed and results
• What is clock speed measured in?

  Gigahertz (GHz)
• How many cycles does 1 GHz represent?

  1 billion cycles
• What happens if a CPU cannot keep up with its clock speed?

  It may corrupt its data
• What is the effect of a very fast clock speed?

  It can cause the CPU to overheat
• How does cache size affect CPU performance?

  More cache allows faster data access
• What is an embedded system?

  A small computer inside a larger system
• How do embedded systems differ from general-purpose systems?

  Embedded systems have one specific function
• What is the primary storage composed of?

  RAM and ROM
• What is the difference between RAM and ROM?

  RAM is volatile, ROM is non-volatile
• What is virtual memory used for?

  To overflow when RAM is full
• What is secondary storage?

  Non-volatile storage that retains data offline
• How does an HDD store data?

  By flipping magnetic polarity
• What is the main advantage of SSDs over HDDs?

  SSDs are extremely fast to access
• What is the basic unit of data?

  Bit
• How many bits are in a byte?

  8 bits
• How do you convert denary to binary?

  Subtract from the largest base 2 number
• What is the result of adding binary digits 1 + 1?

  0, carry 1
• What is hexadecimal?

  A base 16 system for binary representation
• How do you convert hexadecimal to denary?

  Convert hex digits to nibbles, then denary
• What does a left binary shift do?

  Multiplies the number by 2
• How is an image represented in binary?

  As a series of pixels with specific codes
• What affects an image's size and quality?

  Colour depth and resolution