computer architecture

Question 1

whats a CPU?

Answer 1

central processing unit

key component of a computer system,
which contains the circuitry necessary to fetch,
decode and execute program instructions from
and to main memory (RAM).

Question 2

whats ALU?

Answer 2

arithmetic logic unit

it does arythmetical and logic functions
sometimes referred to as ‘core’
single core works slower than dual core (imagine small ducklings and small swans swimming in only one slide and then two slides for each like duckling only and little swan onlu slide, the second model is faster and more efficient and birds can get to the slide and get happy faster)

Question 3

whats CU?

Answer 3

control unit

it handles the loading of new commands into
the CPU and the decoding of these commands.
also, it directs the data flow and the operation
of the ALU.

Question 4

whats MAR?

Answer 4

memory address register

is connected to the address bus.
is contains a memory address.
MAR’s sole function contain the RAM address of the
instruction the CPU wants next.

Question 5

whats MDR?

Answer 5

memory data register

MDR is connected to the data bus.
MDR holds data that will be written to the RAM or that was
read from RAM.
relationship between MAR & MDR: the MAR gives the
address the data of the MDR will be read from or written to.

Question 6

very very simple model of computer working

Answer 6

theres a CPU and everything mentioned earlier (ALU, MAR, MDR, CU and other registers) is inside it, except for RAM and cache
cache is connected with both RAMand CPU wih a data bus.
theres also two busses going in direction of CPU -> RAM called address and controll bus.

Question 7

and how does input output work on cpu?

Answer 7

the output, input and storage device are connected to the cpu

Question 8

!! THIS WILL BE ON THE TEST.
try drawing the cpu organisation system

Question 9

in short present busses.

Answer 9

Busses are the connecting wires that
connect the CPU to other devices,
carrying instructions to/from
components.
They are normally built into the
motherboard.
The three most important busses are:
* Data bus (links RAM to CPU via MDR)
* Control bus (links RAM to CPU via CU)
* Memory bus (links RAM to CPU via MAR)

Question 10

whats a register?

Answer 10

small, fast circuits that store indeterminate values from calculations or conclusions inside cpu.

Question 11

what registers do you know?

Answer 11

there are many, but we must know only three:
MAR
MDR
Accumulator

Question 12

describe the memory sistem.

Answer 12

memory is divided into primary and secondary. primary is ROM, RAM and cache. secondary is magnetic, optical and electronic.

Question 13

whats ROM

Answer 13

it states for READ ONLY MEMORY. originally its contents were static (hence ‘read only’) and could not be hanged – not true any more (flash upgrades).
it is non-volatile = does not lose its contents if power is lost
it stores the BIOS (Basic Input Output System) – a small program that allows the computer to know what to do to find the operating system to ‘boot’ the computer after power is restored.

Question 14

whats RAM

Answer 14

often referred to as primary memory, (so usually in tests it will be referred to as “memory”, unless stated otherwise) means RANDOM ACCES MEMORY. it contains the data and instructions the computer has loaded since starting up and everything the user has opened/loaded. it is volatile = loses its contents if power is lost. it has as a special link to the CPU (via busses)

Question 15

can RAM and ROM both be easily upgraded?1

Answer 15

No, ROM is usually part of motherboard and its difficult to upgrade.

Question 16

explain cache memory

Answer 16

small, high-speed memory inside the 1CPU used to hold frequently used data, so that the CPU needs to access the much slower RAM less frequently

Question 17

list the memory tools from the heaviest to the lightest.

Answer 17

offline storage (tape drivers), hard disk, RAM, cache and the cpu registers.