1.2 Mermory Flashcards
What are features of RAM?
Random access memory
- Where programs currently in use are stored
- RAM stores 2 things the CPU needs;data and instructions
- Volatile-loses data when power is lost
- Read and write
What are the features of ROM?
Read only memory
- stores the information needed to boot up the computer
- contains the BIOS (Basic Input Output System) that lets you use a keyboard, mouse and displays things to the screen
- non-volatile -keeps its data even when the power is turned off.
- Like it’s name suggests it cannot easily be written to and is designed to be read from only.
What’s the purpose of the ROM?
The BIOS is stored in ROM. The BIOS controls what happens when the computer is first switched on. Also known as the bootstrap loader
What’s the purpose of RAM?
It can take a long time to fetch data and program instructions from the hard drive. So it’s stored in the RAM, a temporary store of data, so data can be retrieved quickly by the CPU when required for the program it’s running.
-holds the information currently in use by the computer
What’s firmware?
Permanent software programmed into ROM
What’s BIOS?
BIOS – Basic input/output system contains programs to load the hardware
What’s disc thrashing?
DISK THRASHING- when a computer’s virtual memory subsystem is in a constant state of paging
What’s virtual memory?
•Virtual memory is simply an area of secondary storage that is used like RAM.
•It is temporary storage
•It is located on the hard disk
-virtual memory is there to stop the computer from crashing from lack of memory, when RAM gets overloaded
-the least recently used programs can be swapped out of RAM into virtual memory to make for new programs in RAM
What are the advantages and disadvantages of having virtual memory?
Advantages • You can run more applications at once • You can run larger applications with less real RAM • You don't have buy more memory RAM Disadvantages • Applications run slower • It takes more time to switch between applications • Less hard drive space for your use
What is flash memory?
•A type of rewritable, non-volatile memory that is used in countless modern storage situations: e.g. USB pen drives, SD cards, Internal storage on phones and mp3 players, Solid state drives
What’s DRAM?
Dynamic RAM
-type of memory that requires the data to be refreshed so often so the data isn’t lost(through capacitor leakage) -less expensive than SRAM
What’s SRAM?
Static RAM
-type of memory that doesn’t need to be refreshed, more expensive than DRAM
