01 Section 1 - Computer Systems and the CPU

Question 1

What is a computer?

Answer 1

A computer is a machine that processes data

Question 2

What is the purpose of a computer?

Answer 2

To take data in, process it and then output it

Question 3

What does a computer system consist of?

Answer 3

Hardware and software

Question 4

What is hardware? (and what are some examples)

Answer 4

Hardware is the physical stuff that makes up a computer

CPU, Motherboard, Monitor, Printer

Question 5

What is software? (and what are some examples)

Answer 5

Software is the programs or applications that a computer system runs
(an operating system, a word processor, video game)

Question 6

What are external pieces of hardware called?

Answer 6

Peripherals

They are external pieces of hardware like the keyboard, mouse and printers.

Question 7

What are embedded systems?

Answer 7

Embedded systems are computers built into other devices

they are dedicated to a single task

Question 8

What are some examples of embedded systems?

Answer 8

Dishwashers
Washing machine
Microwaves
Central heating systems

Question 9

What are embedded systems often used as?

Answer 9

Embedded systems are often used as control systems, they monitor and control machinery in order to achieve a desired result

Question 10

What are the main hardware components of a computer?

Answer 10

Power supply
Case cooling fan
CPU heat sink and cooling fan
CPU
Graphics Card
Motherboard
Hard Disc Drive
RAM sticks
Ghost
Optical drive

Question 11

What is the motherboard?

Answer 11

The main circuit board in the computer, where the hardware is connected

Question 12

What does CPU stand for?

Answer 12

Central Processing Unit

Question 13

What is the CPU?

Answer 13

It’s the brain of a computer system

-it processes data and instructions that make the system work

Question 14

What does the CPU architecture describe?

Answer 14

• the main components of the CPU
• how the components interact with each other
• how the components interacts with other parts of the computer system

Question 15

What are the two main types of architecture?

Answer 15

Von Neumann

Harvard

Question 16

What does CU stand for?

Answer 16

Control Unit

Question 17

What does ALU stand for?

Answer 17

Arithmetic Logic Unit

Question 18

What does PC stand for?

Answer 18

Program Counter

Question 19

What does MAR stand for?

Answer 19

Memory Address Register

Question 20

What does MDR stand for?

Answer 20

Memory Data Register

Question 21

What does ACC stand for?

Answer 21

Accumulator

Question 22

What are the three buses between the CPU and RAM?

Answer 22

Address bus
Control bus
Data bus

Question 23

What is the CU?

Answer 23

The CU is in overall control of the CPU.

-job is to execute program instructions by following the fetch-decode-execute cycle

Question 24

What does the ALU do?

Answer 24

All the calculations

-operations, comparisons, logic operations and binary shifts

Question 25

What is cache?

Answer 25

Cache is very fast memory in the CPU (slower than the registers, but quicker than RAM)

Question 26

What does cache store?

Answer 26

Regularly used memory, the CPU goes to cache first to look for data and then RAM if it can't find it in cache

Question 27

What are the features of cache memory?

Answer 27

very low capacity | expensive

Question 28

What does the Program counter do?

Answer 28

holds the memory address of the instructions for each cycle

Question 29

What does the ACC do?

Answer 29

stores intermediate results of calculations in the ALU

Question 30

What does the MAR do?

Answer 30

holds any memory address about to be used by the CPU | -the address might point to data or a CPU instruction

Question 31

What does the MDR do?

Answer 31

holds the actual data or instruction | -this may have been fetched from memory or might be waiting to be written to memory

Question 32

What is in the Fetch process from the Fetch- Decode- Execute cycle?

Answer 32

- copy the memory address from the PC to the MAR - carry out address location in memory from the MAR down the address bus and back out the data bus to the MDR - copy data in MDR to the CIR - increment in PC(ready for the next cycle)

Question 33

What is in the Decode process from the Fetch- Decode- Execute cycle?

Answer 33

- the instruction in the MDR is decoded by the CU | - the CU then prepares for the next step

Question 34

What does CIR stand for?

Answer 34

Current Instruction Register

Question 35

What is in the Execute process from the Fetch-Decode- Execute cycle?

Answer 35

-the instruction is performed | this could be load, write, do a calculation, logic operation, change the address in the PC, halt the program

Question 36

What are the registers in the CPU?

Answer 36

PC MAR MDR CIR

Question 37

What are registers?

Answer 37

They are on the CPU and temporarily hold tiny bits of data needed by the CPU. -they are super-quick to read/write to