A p p e n d i c e s
182
CHS Translation
Cylinder, head and sector translation.
Conversion of hard disk access addressing to
the cylinder, head and sector form. The termi-
nology is historical left from the days when data
was stored on a series cylindrical drums. The
head designates the reading device, similar to
the head on your cassette recorder only
mounted on a movable arm. Another
addressing method is LBA.
CMOS RAM
Complementary metal oxide semiconductor
random access memory. This is a technology
for manufacturing random access memory
wh i ch requ i res very low levels of power to opera te .
COM Port
Abbreviation for communication port.
This is your serial interface connection to
other equipment.
Command
An instruction which you give your operating
system. Example: run a particular application
or format a floppy disk.
Configuration
The combination of hardware and software
that makes up your system and how it is
allocated for use.
CRT
Cathode Ray Tube.A display device which uses
a beam of electronic particles striking a lumi-
nescent screen. It produces a visual image by
varying the position and intensity of the beam.
Data
The information a system stores and processes.
DC
Direct current.A voltage or current that does
not fluctuate periodically with time.
Default Value
A preprogrammed value to be used if you fail
to set your own.
DIMM
Dual-in-line memory module.
Disk
A spinning platter of magnetic data storage
media. If the platter is very stiff it is a hard disk,
if it is highly flexible it is a floppy disk,if it is a
floppy disk in a hard housing with a shutter it is
commonly called a diskette.
Disk Drive
The hardware which spins the disk and has the
heads and control circuitry for reading and
writing the data on the disk.
Diskette
A floppy disk in a hard housing with a shutter.
DMA
Direct Memory Access.Special circuitry for
memory to memory transfers of data which do
not require CPU action.
