October, 1996
6880902Z36-B
2-9
GM300 Radio Service Software Manual
Getting Started
Understanding Computer Basics
2
ate at the keyboard, or from data copied from a dis-
kette. Hard disks can store from 20 megabytes (1
megabyte(MB) = 1 million characters) to over
100MB of data, depending on model type. Most
hard-disk drives are labelled as the “C” drive.
4.
Diskettes and Diskette Drive
Diskettes also store users' programs and files, but
are different from hard disks because of their trans-
portable, small size and packaging. A diskette must
be “formatted” before storing your files and pro-
grams on it. After a diskette is inserted into a dis-
kette drive, data on the magnetic diskette can be
retrieved, stored, manipulated or erased. The oper-
ation of the diskette drive is also similar to the
record-player concept described in the hard disk
subsection.
Diskettes come in two sizes: 3.5 inch and 5.25 inch. Each diskette size has two memory capacities - low
density and high density. The table below shows the memory capacity of both diskette size.
The RSS program is distributed to you on one 3.5" low density diskette and two 5.25" low density dis-
kettes so that it may be easily loaded onto any appropriate computer, regardless of the type of diskette
drive that is available. Handle the diskettes carefully - avoid contact with the shiny, brown, magnetic disk
surface under the protective plastic cover on the 5.25" diskette and the magnetic disk surface under the
sliding metal plate on the 3.5" diskette. Such contact could damage the data and make it unreadable by
the drive.
Diskette drives come in two sizes; one to accommodate the 5.25" diskettes and one to accommodate the
3.5" diskettes. With the 5.25" diskette drives, after inserting a diskette as far as it will go, you must close or
push down the “drive door” located on the outside of the drive or else the computer will not read the
data on the diskette. This drive door generally swings down and locks into place when firmly pressed,
and it releases when gently pressed back the other direction when you want to remove your diskette.
With the 3.5" diskette drives, the diskette is inserted into the slot until it locks into place. The drive does
not have a door like the 5.25" drive. Instead it has an eject button, which when pressed firmly will release
the diskette.
Most diskette drives are labelled “A” or “B”, with “A” generally being the first (or highest) one. The
drives are sometimes labelled by the computer dealer before delivery to the customer.
Though it requires more steps, it is possible to run the RSS with only one diskette drive and no hard
drive. Most businesses today have computers equipped with at least two drives, whether they are a hard
drive and a diskette drive or two diskette drives. Instructions, steps, tables and procedures that apply to
computers with only diskette drives (no hard disk drive) will be displayed in a shaded box.
Table 2-4.
Diskette Size and Capacity
Size
Low Density
High Density
3.5 inch
720K
1.44MB
5.25 inch
360K
1.2MB
