Commodore 128D - Page 410

Octave: One full series of eight notes on the musical scale.
Operating System: A built-in program that controls everything your
computer does.
Operator: A symbol that tells the computer to perform a mathemati
cal, logical or relational operation on the specified variables,
constants or array elements in the expression. The mathemati
cal operators are + ,-,*,/ and t. The relational operators are
<, =,>,< =,> = and < >. The logical operators are AND, OR
NOT.andXOR.
Order of Operations: Sequence in which computations are per
formed in a mathematical expression. Also called Heirarchy of
Operations.
Parallel Port: A port used for transmission of data one byte at a time
over multiple wires.
Parity Bit: A1 or 0 added to a group of bits that identifies the sum of
the bits as odd or even.
Peripheral: Any accessory device attached to the computer such
as a disk drive, printer, modem or joystick.
Pitch: The highness or lowness of a tone that is determined by the
frequency of the sound wave. See Frequency.
Pixel: Computer term for picture element. Each dot on the screen
that makes up an image is called a pixel. Each character on the
screen is displaced within an 8 x 8 grid of pixels. The entire
screen is composed of a 320 x 200 pixel grid. In bit-map
mode, each pixel corresponds to one bit in the computer's
memory.
Polling: A communications control method used by some computer/
terminal systems whereby a "master" station asks many
devices attached to a common transmission medium, in turn,
whether they have information to send.
Pointer. A register used to indicate the address of a location in
memory.
Port: A channel through which data is transferred to and from the
CPU. An 8-bit CPU can address 256 ports.
406 GLOSSARY