Paper 1 Red Flashcards
(31 cards)
What does the Control Unit (CU) do?
In charge of the FDE cycle and moves data around the system
What does the Arithmetic Logic Unit do?
Does logical and numerical calculations, acts as a gateway between primary memro yand secondary storage
What does the cache do?
The cache is a small amount of high-speed RAM built directly inside the CPU, it holds frequently used intructions for quick access.
What does the clock do?
Sends out regular puleses to keep components syncronized
What are the 3 buses?
Address Bus: Carries data address from the processor to other components such as input/ output devices, carries data from the MAR to the RAM to recieve the data
Control Bus: Carries clock signals, carries CU signals to other components
Data Bus: Carries actual data around the system
What does the program counter do?
Holds the address of the next instruction to be executed
Increments by one once the MAR has recieved the value
What does the MAR do?
Holds the address of the instruction that is to be fetched from the primary memory
What does the MDR do?
Holds the data that is too be exectued
What does the CIR do
The Current Instruction Register holds the instruction while it is being executed by the CU or ALU
What does the accumulator do
Holds the result of a mathmatical instruction
What does the CU do?
Sends an instruction to increase the PC value, and decodes the data to be exectuted
Give 2 benefits and 2 negatives of magnetic / hard drive storage
+ Cheap
+ High In capacity
- Suspectible to being dropped
- Can be damaged by magnetic fields
Give 2 benefits and 2 negatives of optical / blu-ray storage
+ Non-volatile storage so not vunerable to data loss
+ Easily transportable
- ROM media cannot be written to
- R-Media can only be written to once
Give 2 benefits and 2 negatives of solid state / electrical storage
+ Portable
+ High speed
- Suspectible to power loss
- Expensive
What are 2 examples of solid state / electrical storage
USB
SD card in phones
What are 2 examples of optical storage
CDS
DVDs
Blu Ray
What are 2 examples of magnetic storage / hard disk drive
Floppy Disks
Magnetic stripes on Credit Cards
What are the different types of optical storage?
ROM media: Have data pretwritten on them and cannot write over them
R Media: Can only write data to it once by burning “pits” into the “lands”
RW Media: Can be written to more than once
How do magnetic storages work?
“Read / write heads” magnetise one tiny part of a spinning disk. Magnetised part reprents one, non magnetised part represents 0. “Read / write heads” can also read by checking if it is magnetised or not
How do solid state / electrical storages work?
They use non-volatile RAM to store data indefinately
How to optical devices work
A spinning disk has many tracks, which contain “lands” (flat areas) and “pits”(hollow areas). Land = 1 and pit = 0. A light shiens to see if it is reflected or not.
List units of data storage in order from smallest to largest
How is the size of a sound file calculated
Duration x sample rate x sample depth
How is the size of an image file calculated
Width x heigh x colour depth
