Computer Science

What is the Control Unit (CU)?

The component of the CPU that manages instructions

What is the ALU?

A component of the CPU that performs arithmetic and logic calculations

Name the five CPU registers

PC, MAR, MDR, CIR, ACCUMULATOR (in order)

What is the cache?

a small amount of RAM storage used to hold frequently used instructions

What is secondary storage compared to primary storage?

Secondary storage is non-volatile, slower, has higher capacity and isn’t close to the CPU

Give examples of secondary storage

SSD, HDD, USB flash drives and optical disks

What is an embedded system?

a small computer that forms part of a larger system

Give examples of embedded systems

fitness trackers, appliances (washing machines or microwaves), GPS, digital watches

What is RAM and ROM?

RAM: random access memory that holds programs and data currently in use, it is volatile (loses data when switched off

ROM: read only memory that stores instructions and data needed for the computer to run, it is non-volatile

What is virtual memory?

Virtual memory is used when the computer has no more available random access memory (RAM). It uses secondary storage such as SSD to temporarily store data and instruct

What does the PC do?

holds the address of the next instruction to be executed

What does the MAR do?

stores the memory address of the data or instruction the CPU needs to read from

What does the MDR do?

temporarily stores data which is read from or written to main memory

What does the CIR do?

holds the current instruction being executed

What does the accumulator do?

holds the result of arithmetic and logical calculations