Flashcards
Computing Revision Cards
Flashcards do conjunto (23)
- 1What is the Control Unit?The control unit is in overall control of the CPU. Its main job is to execute program instructions by following the fetch-decode-execute cycle.
- 2What is the ALU?The ALU does all of the mathematical calculations. It performs logical operations and it contains the accumulator register.
- 3What is the cache?It stores regularly used data so that the CPU can access it quickly the next time it's needed. The CPU checks if the data is in the cache first, if not then it will go to the RAM.
- 4What are the registers?The memory address register (MAR) holds any memory address about to be used by the CPU.
- 5What is the program counter?The program counter (PC) holds the memory address of the instructions for each cycle.
- 6Fetch Instruction1) Copy memory address from the program counter to the MAR.
2) Copy the instruction stored in the MAR address to the MDR.
3)Increment the program counter to point to the address of the next instruction, ready for the next cycle. - 7Decode InstructionThe instruction n the MDR is decoded by the CPU. The CU may then prepare for the next step, e.g by loading values into the MAR or MDR.
- 8Execute InstructionThe instruction is performed. The could be: load data from memory, write data to memory, do a calculation or logic operation (using the ALU), change the address in the PC, or halt the program.
- 9Von Nueman
- 10MARThe MAR holds the address of the current instruction being executed. The MAR knows the location of the data that needs to be accessed. It also keeps track of where the data is located.
- 11Storage MethodsMagnetic: Mechanical parts move over the disks surface to read and write data magnetically.
Optical: Lasers read and write data using light.
Solid State: Data is recorded onto solid memory chips without and moving parts. - 12Magnetic Disks
- 13Flash Memory
- 14Cloud storageAdvantages: It can be accessed anywhere with an internet connection. It doesn’t take up local storage on your device. It saves automatically to the servers. Certain amounts of storage are free.
Disadvantages: No internet connection, no access, Servers go down, no access, prone to cyber security attacks - 15Solid State Drives. Advantages:
. Highly durable, no moving parts, very fast read/write speeds, no noise, faster start up times. - 16Storage TypesPrimary Storage:
. RAM and ROM
. Secondary Storage:
. HDD and SSD
. Offline secondary storage:
. Compact Disc, DVD or Bluray
. USB Flash drive
. Magnetic Tape - 17What does the OS do?
- 18GUIGraphical User interface, it allows the user to control the computer with a mouse or with their finger. They control hardware via drivers and allows the computer to urn applications and multitask.
- 19DefragmentationFiles are stored on a hard disk. Files are moved, deleted, changed. The OS splits files into smaller blocks to fill up the gaps that appear on the disk. Over time the disk becomes more and more fragmented which makes reading and writing slower. De-fragmentation software reorganizes data on the hard drive to put fragmented files back together.
- 20Backup UtilitiesA full backup backups all files on the computer. An incremental backup backs up all the files that were saved on the last backup and ones that have been created since.
- 21Compression SoftwareReduces the size of files so they take up less disk space. It's used on the internet to turn files into .zips and .rar to make them quicker to download. Compressed files need to be extracted before they can be used.
- 22Encryption SoftwareScrambles (encrypts) data to stop third parties from accessing it. Can be decrypted by using a unique "key".
- 23User AccountsIn a network there are different user account levels. The people at the top have access to admin so they can do whatever they want, while people below them are only able to do things that that are restricted by the top level accounts. This stops people from accessing information other people may not want them to, e.g. in a school the students are at the bottom while the technicians are at the top (admin).
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- GCSE Computing FlashCards sobre Computing Revision Cards, criado por Jasper Lawson em 10-07-2019.
- Criado por
- Jasper Lawson
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