Edexcel GCSE Computer Science, Unit 3: Computers Exam
Questions And Answers With Complete Solutions
Updated
von Neumann architecture
Computer design where processing instructions are stored in memory; the stored
program concept
Central Processing Unit (CPU)
Hardware that carries out the computer's processing
Bus
Group of connections between devices in a computer
ALU
Arithmetic / logic unit: part of the CPU that performs calculations and logic operations
Register
Storage location inside the CPU used to hold an instruction, an address or other single
data items
Control unit
Part of the CPU that organises other parts of the CPU
Clock
Part of the CPU that synchronises the actions of the CPU
Main memory / Random Access Memory (RAM)
Temporary storage for data and instructions
Volatile memory
Memory that is lost when the power is switched off, RAM is volatile
Fetch - Decode - Execute
Steps carried out repeatedly by the CPU: instructions are fetched from the memory,
then they are processed and the cycle repeats...
Read-only memory (ROM)
, Non-volatile memory; programs that run when the computer is turned on are kept in
ROM
Non-volatile memory
Data is not lost when the power is switched off
Input - Process - Output model
An input is received, the instruction are processed, an output is given
Embedded systems
Devices (often household devices) that have a processor inside them (remote control,
microwave oven, washing machine, etc) to carry out limited tasks
John von Neumann
Developed the idea that a computer could store instructions in memory
Cache
Very fast Random Access Memory, stores frequently used instructions to speed up
processing
Secondary storage
Where data and instructions are permanently stored
Secondary storage: magnetic
Hard disc drives have spinning discs covered with magnetic material, electromagnets
on read-write heads encode the data
Secondary storage : optical
CDs, DVDs and Blu-Ray discs have data etched into pits on the disc surface, these pits
are read by a laser
Secondary storage: solid-state
SD cards, microSD cards, USB flash drives are solid-state; no moving parts, uses
semiconductor chips, not magnetic media, to store data
Secondary storage: cloud storage
Data is stored in data centres accessible over the internet, Dropbox or Microsoft
OneDrive for instance
Software
The programs that run on a computer. There are two types: application software and
system software
Questions And Answers With Complete Solutions
Updated
von Neumann architecture
Computer design where processing instructions are stored in memory; the stored
program concept
Central Processing Unit (CPU)
Hardware that carries out the computer's processing
Bus
Group of connections between devices in a computer
ALU
Arithmetic / logic unit: part of the CPU that performs calculations and logic operations
Register
Storage location inside the CPU used to hold an instruction, an address or other single
data items
Control unit
Part of the CPU that organises other parts of the CPU
Clock
Part of the CPU that synchronises the actions of the CPU
Main memory / Random Access Memory (RAM)
Temporary storage for data and instructions
Volatile memory
Memory that is lost when the power is switched off, RAM is volatile
Fetch - Decode - Execute
Steps carried out repeatedly by the CPU: instructions are fetched from the memory,
then they are processed and the cycle repeats...
Read-only memory (ROM)
, Non-volatile memory; programs that run when the computer is turned on are kept in
ROM
Non-volatile memory
Data is not lost when the power is switched off
Input - Process - Output model
An input is received, the instruction are processed, an output is given
Embedded systems
Devices (often household devices) that have a processor inside them (remote control,
microwave oven, washing machine, etc) to carry out limited tasks
John von Neumann
Developed the idea that a computer could store instructions in memory
Cache
Very fast Random Access Memory, stores frequently used instructions to speed up
processing
Secondary storage
Where data and instructions are permanently stored
Secondary storage: magnetic
Hard disc drives have spinning discs covered with magnetic material, electromagnets
on read-write heads encode the data
Secondary storage : optical
CDs, DVDs and Blu-Ray discs have data etched into pits on the disc surface, these pits
are read by a laser
Secondary storage: solid-state
SD cards, microSD cards, USB flash drives are solid-state; no moving parts, uses
semiconductor chips, not magnetic media, to store data
Secondary storage: cloud storage
Data is stored in data centres accessible over the internet, Dropbox or Microsoft
OneDrive for instance
Software
The programs that run on a computer. There are two types: application software and
system software
