Specifications

Glossary
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multimedia units have been improved by making
the registers 128 bits wide and adding a separate
register for data movement. Finally, SSE2 adds 144
new instructions for double-precision floating-
point, SIMD integer, and memory management.
The original Socket 423 version (Willamette) was
later replaced by Socket 478 (Northwood) and
finally by Socket 775 (Prescott) running at up to
3.6GHz. 800MHz system bus versions also support
HT Technology.
Pentium 4 Extreme Edition A high-speed
version of the Pentium 4 that includes 2MB of L3
cache. The original versions ran at 3.46GHZ and
were made in Socket 478 and Socket 775. Later
versions boosted the system bus from 800MHz to
1066MHz, used the Prescott core, and ran at
3.73MHz. It has been replaced by the Pentium
Extreme Edition.
Pentium D An Intel seventh-generation proces-
sor (code named Smithfield and Presler) that
includes two Pentium 4 Prescott or Cedar Mill
processor cores in the same processor die. The
Pentium D fits into Socket 775 and was the first
dual-core PC processor, introduced in May 2005.
The Pentium D includes EM64T architecture. See
also EM64T and AMD64.
Pentium Extreme Edition A seventh-
generation EM64T-compatible dual-core processor
based on the Pentium D, but with HT Technology
enabled. Dual-processor–enabled operating systems
treat this chip as having four logical processors.
Requires a different chipset from the Pentium D.
See also Pentium D, EM64T, and AMD64.
Pentium II An Intel sixth-generation processor
similar to the Pentium Pro but with MMX capabili-
ties and SEC cartridge packaging technology.
Includes L2 cache running at half-core speed.
Pentium III An Intel sixth-generation processor
similar to the Pentium II but with SSE (Streaming
SIMD Extensions) added. Later PIII models (code-
named Coppermine) include on-die L2 cache run-
ning at full core speed. It’s available in both
cartridge (Slot 1) and chip package (Socket 370)
versions.
Pentium Pro An Intel sixth-generation (P6)
processor with 32-bit registers, a 64-bit data bus,
and a 36-bit address bus. The Pentium Pro has the
same segmented Level 1 cache as the Pentium but
also includes a 256KB, 512KB, or 1MB of L2 cache
on a separate die inside the processor package. The
Pentium Pro includes an FPU or math coprocessor.
It is backward compatible with the Pentium and
can operate in real, protected, and virtual real
modes. The Pentium Pro fits into Socket 8.
peripheral Any piece of equipment used in
computer systems that is an attachment to the
computer. Disk drives, terminals, and printers are
all examples of peripherals.
persistence In a monitor, the quality of the
phosphor chemical that indicates how long the
glow caused by the electrons striking the phosphor
will remain onscreen.
personal computer (PC) Generically any small
computer that can be used by an individual; more
specifically, a type of personal computer that is
based on the original IBM PC introduced in 1981.
Personal Video Recorder (PVR) See Digital
Video Recorder (DVR).
petabyte (P) A measure of disk capacity equal-
ing 1,000,000,000,000,000 bytes.
PGA 1) Pin grid array. A chip package that has a
large number of pins on the bottom designed for
socket mounting. 2) Professional graphics adapter.
A limited-production, high-resolution graphics card
for XT and AT systems from IBM.
phosphor A layer of electroluminescent material
applied to the inside face of a cathode-ray tube
(CRT). When bombarded by electrons, the material
fluoresces, and after the bombardment stops it
phosphoresces.
phosphorescence The emission of light from a
substance after the source of excitation has been
removed.
Photo CD A technology developed by Eastman
Kodak and Philips that stores photographic images
on a CD-R recordable compact disc. Images stored
on the Photo CD can have resolutions as high as
2,048×3,072 pixels. Up to 100 true-color images
(24-bit color) can be stored on one disc. Photo CD
images are created by scanning film and digitally
recording the images on compact discs. The digi-
tized images are indexed (given a 4-digit code), and
Appendix A
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