UNIT 2 Test terms and explainations

Question 1

MAR

Answer 1

Stores the memory location of data that needs to be accessed.

Question 2

MDR

Answer 2

Stores the data that is being transferred to and from the memory.

Question 3

ACC

Answer 3

Stores results from calculations

Question 4

PC

Answer 4

Stores the address of the next instruction to be accessed

Question 5

ALU

Answer 5

Carries out basic arithmetic calculations and makes decisions on data sent to the processor.

Question 6

CU

Answer 6

Controls how data is moved through the processor and the timing of operations. And the instruction sent to the processor and input/output devices.

Question 7

Explain the FETCH in the FDE cycle

Answer 7

The address is generated by the PC and is carried to the MAR using an address bus. The PC then updates and stores the next memory address. The data/instruction is then carried to the MDR in the processor via a data bus and then stored.

Question 8

Explain the DECODE in the FDE cycle

Answer 8

The data/instruction is then decoded in the CPU to find out if its a piece of data or instruction.

Question 9

Explain the EXECUTE in the FDE cycle

Answer 9

The CPU then performs the instruction. If its related to any input/output devices then the control unit will carry out that instruction. If its a calculation then the ALU will carry out the calculation and store it in the ACC.

Question 10

The purpose of ROM

Answer 10

Read only memory holds all the instructions to start the computer, access built in hardware and load the OS onto the RAM. The contents of the ROM chip are not lost when the computer is turned of making it non-volatile.

Question 11

The purpose of RAM

Answer 11

After the computer system has been booted up, any applications/data opened by the user are stored in the RAM. The RAM has limited space meaning if too many things are loaded into the RAM the computer can slow down as some of the data needs to be moved to secondary storage.

Question 12

What is flash memory

Answer 12

Fast acting info storage used in computers, games consoles ect.

Question 13

What is virtual memory

Answer 13

When the RAM is full, some of the applications are moved to the secondary storage which acts as RAM, this is called virtual memory.

Question 14

Give 1 DIS and ADV of SSD storage

Answer 14

ADV: Faster read/write speeds than optical/magnetic.
DIS: High cost per GB of storage.

Question 15

Give 1 DIS and ADV of MAGNETIC storage

Answer 15

ADV: Very fast access speeds.
DIS: Not that portable/durable.

Question 16

Give 1 DIS and ADV of OPTICAL storage

Answer 16

ADV: Data cannot be accidentally deleted.
DIS: You cannot edit/add data onto it.