Glossary 11

O
operating system
Set of programs that manage the overall operation of the computer.
overwrite
Storing information at a location where information is already stored, thus destroying the
original information.
P
page
A type of message transmission in which a message is sent or received via modem to a
paging device from a computer (with paging communications software) or telephone.
parallel interface
Interface that communicates eight bits at a time.
parallel printer
A printer with a parallel interface.
parameter
A characteristic of a device or system determined by a command or setting whose purpose
is to define or limit the characteristic.
password
A string of characters that the user must enter before the system allows access or system
privileges.
PCI
Peripheral Component Interface/Interconnect. A self-configuring personal computer local
bus designed by Intel. Most modern PCs include a PCI bus in addition to a more general
ISA expansion bus. PCI is a 32-bit bus, but supports a 64-bit extension for new processors,
such as the Pentium II. It can run at clock speeds of 33 or 66 MHz. At 32 bits and 33 MHz,
it yields a throughput rate of
133 megabits per second. 64-bit implementations running at 66 MHz provide
524 Mbps. See ISA.
peripheral
Input or output device not under direct computer control. A printer is a peripheral device.
pixels
Picture elements. Tiny dots that make up a screen image. A pixel is the smallest spot on the
screen that a computer can address.
plug and play
Refers to the ability of a computer system to automatically configure expansion boards and
other devices. This enables a user to plug in a device and use it, without worrying about
setting DIP switches, jumpers, and o ther configuration elements.