Page 52 - DCAP101_BASIC_COMPUTER_SKILLS

Unit 4: Secondary Storage Devices

moves the pickup arm access the CD to the groove where the sixth song begins and starts Notes
playing. Magnetic disks, optical disks, and memory storage devices are examples of direct-
access storage devices.
4.1.1.1 Hard Disks
Hard disks are the primary on-line secondary storage device for most computer systems
today. They are made of rigid metal (frequently aluminum) platters and come in many sizes
ranging from 1 to 14-inch diameter.

Figure 4.1: Hard Disks

Types of Hard Disks
Depending on how they are packaged, hard disks are normally categorized into three types:
1. Zip/Bernoulli Disk. It consists of a single hard disk platter encased in a plastic cartridge.
The disk commonly of 3½-inch size having storage capacity of about 100 MB. The
storage capacity slightly varies depending on the formatting style used by a computer
system with which it is used. Its disk drive, called zip drive, may be of portable or fixed
type. The fixed type is part of a computer system permanently connected to it. The
portable type can be brought and connected to a computer for the duration of use and

can then be disconnected and taken away. A zip disk can be easily loaded/unloaded
into a zip drive just as we insert/remove a floppy disk in a floppy disk drive or a video
cassette in a VCR.

Figure 4.2: A Disk Pack

Lid of the plastic
container
Plastic container

Hard disk platters

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