Specifications

56
Appendix A Glossary
thumbnails of each image on the disc are shown on
the front of the case along with its index number.
Multisession capability enables several rolls of film
to be added to a single disc on different occasions.
photolithography The photographic process
used in electronic chip manufacturing that creates
transistors and circuit and signal pathways in semi-
conductors by depositing different layers of various
materials on the chip.
photoresist A chemical used to coat a silicon
wafer in the semiconductor manufacturing process
that makes the silicon sensitive to light for
photolithography.
physical drive A single disk drive. DOS defines
logical drives, which are given a specifier, such as
C: or D:. A single physical drive can be divided into
multiple logical drives. Conversely, special software
can span a single logical drive across two physical
drives.
Physical Layer See OSI.
physical unit number See PUN.
PICMG The PCI Industrial Computers
Manufacturers Group is a trade association that
develops standards for single-board and industrial
computers. Its standards include AdvancedTCA,
CompactPCI, and others. See also AdvancedTCA
and CompactPCI.
Picture CD A simplified version of Photo CD
that stores scanned images from a single roll of film
on a CD-R disc. Images on Picture CDs, unlike
those on Photo CDs, are stored in the industry-
standard JPEG file format and can be opened with
most photo-editing programs.
PIF (program information file) A file that
contains information about a non-Windows appli-
cation specifying optimum settings for running the
program under Windows 3.x. These are called prop-
erty sheets in 32-bit Windows.
PIN (Personal Identification Number) A
personal numeric password used for identification
purposes.
pin The lead on a connector, chip, module, or
device.
pin compatible Chips having the same pinout
functions. For example, a VIA C3 processor is pin
compatible with an Intel Celeron (Socket 370
version).
pinout A listing of which pins have which func-
tions on a chip, socket, slot, or other connector.
PIO mode (programmed input/output
mode) The standard data transfer modes used by
IDE drives that use the processor’s registers for data
transfer. This is in contrast with DMA modes,
which transfer data directly between main memory
and the device. The slowest PIO mode is 0, and the
fastest PIO mode is mode 4 (16.66MBps). Faster
modes use Ultra DMA transfers. See also Ultra DMA.
pipeline A path for instructions or data to
follow.
pixel A mnemonic term meaning picture element.
Any of the tiny elements that form a picture on a
video display screen. Also called a pel.
pixels per inch (ppi) A measurement of resolu-
tion used primarily by video displays and monitors.
pixel shader A small program that controls the
appearance of individual pixels in a 3D image.
Most recent mid-range and high-end GPUs such as
NVIDIA’s GeForce 3 and GeForce 4 Ti series and the
ATI 8xxx and 9xxx series have built-in pixel
shaders. See also GPU, hardware shader, and vertex
shader.
PKZIP The original ZIP-format
compression/decompression program developed by
the late Phil Katz. His company, PKWARE, contin-
ues to develop PKZIP for popular operating systems,
including Windows.
planar board A term equivalent to mother-
board, used by IBM in some of its literature.
plasma display A display technology that uses
plasma (electrically charged gas) to illuminate each
pixel.
plated media Hard disk platters plated with a
form of thin metal film medium on which data is
recorded.
platter A disk contained in a hard disk drive.
Most drives have two or more platters, each with
data recorded on both sides.
24_0789736977_AppA.qxd 8/15/07 9:24 AM Page 56