COMPUTING GCSE OCR COMPONENT 1.1 SUMMARY
Key Terms
Accumulator - (ACC) holds the data which is currently being processed. It stores the results of the
processes from the ALU.
ALU – The part of the CPU which performs arithmetic calculations and deals with logical operators.
BIOS – Basic Input Output System. It is responsible for booting up the system.
Cache – a very small amount of very fast memory which stores regularly used data.
Clock Speed – the number of cycles per second performed by a computer.
Control Unit – The part of the CPU monitoring and managing hardware, inputs and outputs as well
as carrying out the Fetch-Decode-Execute cycle.
CPU – The component of a computer system which processes data and instructions.
Current Instruction Register - (CIR) holds the current instruction being processed.
Embedded System – a system designed to perform one specific function.
Memory Address Register – (MAR) register which holds the address from memory that is about to
be used by the CPU.
Memory Data Register – (MDR) register which holds the actual data which has either been fetched
from or will be written to memory.
Program Counter – holds the address of the next instruction to be fetched by the CPU.
RAM – used to store data the CPU is currently using for currently running programs.
ROM – when you boot up a system, it uses ROM. It is read-only memory.
1.1.1
Main components of a computer system;
CPU – it processes the data and instructions which make a computer work.
RAM – stands for Random Access Model. It stores data, files and programs while they are being
used.
Key Terms
Accumulator - (ACC) holds the data which is currently being processed. It stores the results of the
processes from the ALU.
ALU – The part of the CPU which performs arithmetic calculations and deals with logical operators.
BIOS – Basic Input Output System. It is responsible for booting up the system.
Cache – a very small amount of very fast memory which stores regularly used data.
Clock Speed – the number of cycles per second performed by a computer.
Control Unit – The part of the CPU monitoring and managing hardware, inputs and outputs as well
as carrying out the Fetch-Decode-Execute cycle.
CPU – The component of a computer system which processes data and instructions.
Current Instruction Register - (CIR) holds the current instruction being processed.
Embedded System – a system designed to perform one specific function.
Memory Address Register – (MAR) register which holds the address from memory that is about to
be used by the CPU.
Memory Data Register – (MDR) register which holds the actual data which has either been fetched
from or will be written to memory.
Program Counter – holds the address of the next instruction to be fetched by the CPU.
RAM – used to store data the CPU is currently using for currently running programs.
ROM – when you boot up a system, it uses ROM. It is read-only memory.
1.1.1
Main components of a computer system;
CPU – it processes the data and instructions which make a computer work.
RAM – stands for Random Access Model. It stores data, files and programs while they are being
used.
