Chapter 5 - Computer Hardware Flashcards
What does CPU stand for?
Central Processing Unit
What are the main 3 components of a CPU?
Control Unit
Arithmetic and Logic Unit (ALU)
Immediate Access Store (IAS)
What are the 3 main jobs of the Control Unit?
Decide which instruction to carry out next and fetch it from memory
Decode the instruction
Execute the instruction
What is the function of the ALU?
Arithemtic calculations - addition, subtraction, etc
Logical operations - AND, OR, NOT
What is the function of the IAS?
Also known as main memory or primary memory.
The IAS stores all programs and data while they are in use.
What are the 5 registers used in the fetch-execute cycle?
Program Counter (PC)
Memory Address Register (MAR)
Memory Data Register (MDR)
Instruction Register (IR)
Accumulator
What is the function of the Program Counter (PC)?
The PC is a register in the CPU that holds the address of the NEXT instruction to be executed
What is the function of the Memory Address Register (MAR)?
The MAR is a register in the CPU that holds the address of the CURRENT instruction that is being executed
What is the function of the Memory Data Register (MDR)?
The MDR is a register in the CPU that temporaily holds any data that is being fetched from, or written to, the IAS.
What is the function of the Instruction Register (IR)?
The Instruction Register is a register in the CPU that holds the INSTRUCTION that is currently being decoded and executed
What is the function of the Accumulator?
The ACC is a register in the CPU that stores the results of any calculations that take place
What are the 3 factors that influence the speed of processing?
Clock Speed
Cache
Processor Cores
What is clock speed?
Clock speed is an indicator of the speed at which the processor can operate.
It represents how many instruction cycles the CPU can perform in a second
Faster clock speed = more instructions per second = faster processing speed
What are the units used to measure clock speed?
Clock speed is usually measured in Gigahertz (GHz)
1 GHz = 1 billion cycles per second
What is processor cache?
Cache is a small capacity, but very fast, memory that is located between the CPU and RAM.
Bigger cache = faster processor speed.
How many cores does a dual core processor have?
Dual core = 2 processor cores.
How many cores does a quad core processor have?
Quad core = 4 processor cores
How does the number of cores affect processing speed?
More cores = faster processing
List 4 input devices
Mouse
Keyboard
Microphone
Graphics digitiser
List an input/output device
Touch screen
List 4 output devices
Printer (laser printer or inkjet printer)
Monitor
Speakers
3D Printer
List 3 external storage devices
Hard Disk Drive (HDD)
Solid State Drive (SSD)
Memory Card
What does non-volatile mean?
Non volatile storage can keep data whenever the power is turned off
What are the 3 main types of external storage?
Magnetic Storage (Hard disk, magnetic tape)
Flash Storage (SSD, Memory cards, pen drives)
Optical Storage (CD’s, DVD’s, Blu-ray disks)
What are the 3 types of internal memory?
RAM (Random Access Memory)
ROM (Read Only Memory)
Cache
What is volatile memory?
Volatile memory needs power to store data.
When the power is turned off, all data is lost.
Which 2 types of internal memory are volatile?
RAM
cache
What is the function of RAM?
RAM stores programs and data that are currently being executed
Programs and data must be loaded from external storage when they are being run.
What is the function of ROM?
ROM cannot be written to, so is used to permanently store programs that are frequently use db ythe computer.
The ‘boot-up’ files needed when the computer starts are stored on ROM
What is the function of cache memory?
Similar to RAM but smaller and faster!
