Computer organisation

Question 1

Purpose of the control unit

Answer 1

Coordinates all activities of the CPU

Question 2

What does the control unit make extensive use of

Answer 2

Status register and clock

Question 3

What is the purpose of the status register

Answer 3

Contains information about the state of the processor

Question 4

What is the purpose of the clock

Answer 4

Synchronises related components by generating pulses at a constant rate

Question 5

What is clock speed measured in

Answer 5

Hertz (Hz)

Question 6

What is the purpose of the ALU

Answer 6

Performs arithmetic and logical operations

Question 7

What are the general purpose registers

Answer 7

Tiny areas of extremely fast memory located in the processor normally designed for a specific purpose

Question 8

What is the purpose of the program counter

Answer 8

Holds the address of the next instruction to be executed

Question 9

What is the purpose of the memory address register

Answer 9

Holds the address of the memory location from which data or an instruction is fetched from

Question 10

What is the memory buffer register

Answer 10

Used to temporarily store the data which is read from or written to memory

Question 11

What is the purpose of the CIR

Answer 11

Holds the current instruction being executed

Question 12

How does Von Neumann architecture work

Answer 12

Instructions and data share the same memory space and format, uses a single control unit or processor, one instruction at a time, registers are used as fast access to instructions or data

Question 13

How does Harvard architecture work

Answer 13

Instruction and data are stored in separate memory units, each has its own bus, reading and writing data can be done at the same time as fetching an instruction, used by RISC processors

Question 14

What does the accumulator do

Answer 14

stores the result of the ALU

Question 15

What are buses

Answer 15

Communication channels

Question 16

What does the address bus carry

Answer 16

Address of instruction

Question 17

What does the data bus carry

Answer 17

Carries data from and to the RAM

Question 18

What does the control bus do

Answer 18

Sends control signals from and to the processor

Question 19

What is the instruction made up of

Answer 19

Opcode + operand

Question 20

What is the opcode

Answer 20

What we need to do (OPeration)

Question 21

What is the operand

Answer 21

What do we need to do it to (can contain actual data or an address where the data is found)

Question 22

In an 8-bit instruction which bit is the addressing mode

Answer 22

4th bit

Question 23

What bits are the basic machine operation in an 8-bit instruction

Answer 23

1st, 2nd, 3rd bits

Question 24

In an 8-bit instruction which bits are the operand

Answer 24

5th, 6th, 7th, 8th bit

Question 25

In an 8-bit instruction how many different Opcode are available

Answer 25

16

Question 26

What does “fetch” mean in the FDE cycle

Answer 26

The binary code in the program counter is copied to the MAR which is then put through the ram to get a binary code out which then the control bus sends a signal to read the memory, then the binary code gets sent through the data bus into the memory data register and then into the current instruction register

Question 27

What does “decode” mean in the FDE cycle

Answer 27

The Current instruction register contains the opcode and the operand, then the operand is searched in the decode unit and then searches for the instruction

Question 28

What does “execute” mean in the FDE cycle

Answer 28

MAR receives the address that is needed by the decode unit and then puts it through the RAM and then through the data bus into the MDR and then into the accumulator after receiving a signal from the control unit

Question 29

What are the most common types of storage devices

Answer 29

Optical, magnetic and solid state

Question 30

Which storage device has the most capacity

Answer 30

Magnetic

Question 31

What are the optical storage devices

Answer 31

Blu-ray, CD and DVD

Question 32

How do optical storage devices work

Answer 32

They work by being scanned by a laser and data is stored in pits and lands

Question 33

What are the positives for optical storage

Answer 33

Cheap, light weight, portable

Question 34

What are the negatives for optical storage

Answer 34

Slow access times, prone to scratches

Question 35

What are the positives for magnetic storage

Answer 35

Cheap, large capacity

Question 36

What are the negatives for magnetic storage

Answer 36

Slow access times, fragile

Question 37

How do solid state drives work

Answer 37

Flow of electricity forcing electrons into floating gates between oxide layers, electrons then change lanes which signifies a 1 or 0

Question 38

Positives for a solid state drive

Answer 38

Durable, fast access times

Question 39

What are the negatives for solid state drives

Answer 39

Cost, limited read/writes

Question 40

Why do magnetic storage devices eventually fail

Answer 40

Moving parts eventually break