Name: M LUQMAN KHAN. Program: BSCS (A) ROLL NO: F12-1141

Main Memory Main Memory Organization Main Memory Capacity Random Access Memory Read only-Memory Programmable Read-only Memory Erasable Programmable Read-only

Memory Cache Memory

Every main memory is directly attached to the motherboard .

Every computer can not display the result with out main memory.

Storage Capacity Access Time Cost per bit of storage Volatile Random Access

A primary storage or main memory of computer system is made up of several small storage area called location or cell.

Each of these location can be store a fixed number of bit called word length of the memory.

Main memory capacity of a large computer system is normally more then that of smaller system.

Memory capacity normally stated Kilobytes 1024 (bytes) Megabytes 1048576(bytes) Gigabytes 107374824 (bytes)

RAM is the volatile memory.

RAM memory consist of some integrated circuit chip either on the motherboard or on a small circuit board attached to the motherboard.

A special type of RAM called ROM.

It is non-volatile memory chip in which data to stored permanently.

Data store in a ROM chip can not be change.

There are tow types of PROM.

A manufacturer programmed ROM one which data is burnt in by the manufacturer of electronic equipment.

A user PROM is which a user can load and store “read-only” programs and data.

There are tow types.

Ultra violet EPROM Electrically EPROM Flash memory

The Cache memory is a small memory directly accessible by the processor.

Small size, extremely fast.

When ever data is required by the processor it first checks in the Cache.

Current cache size is 2MB or more.