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ROM
It stores a set of pre-defined instructions for the internal operations of a
computer. It is also referred as non-volatile memory or firmware.
Once the user switches ON the computer, the computer automatically does
a series of sequential tasks like POST (Power On Self Test), RAM Test, etc.
before the user starts his work.
The instructions for such predefined set of tasks are stored in the ROM. Such information on this memory
can only be read. There are different types of ROM like PROM, EPROM, EEPROM, Flash ROM. ROM helps
in starting or booting the system by executing the BIOS ( Basic Input Output System) commands.
BIOS pronounced as Bye-ose, is stored in ROM and it operates when the computer is switched ON. It
contains a set of essential softwares that test the setup of hardware devices during startup. It helps to
start the operating system and supports the transfer of data among the hardware devices.
Besides RAM and ROM, there are some other primary memories like the Cache or Buffer memory. Cache
Memory is a part of CPU and is used when there is swapping of information between the primary memory
and the ALU. Cache can be of two types:
Primary Cache: A primary cache is always located on the CPU. This cache is similar to register in
l
terms of size and access time.
l Secondary Cache: A secondary cache is placed between the CPU and memory. This cache is slower
than primary cache in terms of access time but bigger in size as compared to primary cache.
Secondary Memory/Auxiliary Memory
Secondary memory refers to the permanent storage of data. During the operation of computer, the
currently used data lies in the temporary memory. It may get lost, if the computer is suddenly switched
OFF. For such a purpose secondary memory is required, as it provides necessary backup and storage of
instruction or data that are permanent and can be retrieved back as and when required. It is also known
as backup memory. It has higher storage capacity than the primary storage/memory. There are various
types of secondary storage devices. Some of them are:
Magnetic Disks
Magnetic Disks are storage devices that are made up of magnetic coated material.
Platter
Spindle
Head
Head Actuator Arm
Actuator Axis
and Pivot Screw
Voice Coil Power Connector
Actuator
Jumper Block
Ide Connector On Printed
Circuit Board (Interface)
26 Touchpad Computer Applications (Ver. 2.0)-IX

