Physical Characteristics of Memory

1. Volatile ~ Non-Volatile 

• Volatile memory: A temporary memory that loses its contents when the computer or hardware device loses power, memory storage type is not permanent.  

SDRAM

    Example: RAM (EDO-RAM, SDRAM, DDRAM).

• Non-Volatile memory: A memory that keeps its contents even if the power is lost, storage in this type of memory is permanent.

Memory Access Method

 There are 4 Memory Access Method:

 
1. Sequential Access Method

Sequential Access

• Data access is very slow, because the data will be sorted access serially one by one.
• Data access is done sequentially, such as on magnetic tape.

    Example: Magnetic Tape, Cartridge Back Up.

 

2. Direct Access Method

Direct Access

 

• obtain data from a storage device by going directly to where it is physically located on the device rather than by having to sequentially look for the data at one physical location after another.
• Data-access relatively quickly, compared Sequential Access.

    Example: Hard Disk, Floppy Disk (floppy).