Commodore 128 Programmer's Reference Manual page 745

GLOSSARY 735
n
Half-Duplex Mode: In this mode, data can be transmitted in only one direction at a
time; if one device is sending, the other must simply receive data until it's time for
it to transmit.
Hardware: Physical components in a computer system, such as the keyboard, disk
drives and printer.
Hexadecimal: Refers to the base-16 number system. Machine language programs are
often written in hexadecimal notation.
Home: The upper-left corner of the screen.
IC: The abbreviation for Integrated Circuit. A silicon chip containing an electrical
circuit made up of components such as transistors, diodes, resistors and capaci
tors. Integrated circuits are smaller, faster and more efficient than the individual
circuits used in older computers.
Increment: To increase an index variable or counter with a specified value.
Index: The variable counter within a programming loop.
Input: Data fed into the computer to be processed. Input sources include the keyboard,
disk drive, Datassette or modem.
Integer: A whole number (i.e., a number containing no fractional part), such as 0, 1,
2, etc.
Interface: The point of meeting between a computer and an external entity, whether an
operator, a peripheral device or a communications medium. An interface may be
physical, involving a connector, or logical, involving software.
I/O: The abbreviation for Input/Output. Refers to the process of entering data into the
computer, or transferring data from the computer to a disk drive, printer or storage
medium.
Keyboard: Input component of a computer system.
Kilobyte (K): 1024 bytes.
Local Network: One of several short-distance data communications schemes typified
by common use of a transmission medium by many devices at high-data speeds.
Also called a Local Area Network, or LAN.
Loop: A program segment executed repetitively a specified number of times.
Machine Language: The lowest-level language the computer understands. The com
puter converts all high-level languages, such as BASIC, into machine language
before executing any statements. Machine language is written in binary form, which
a computer can execute directly. Also called machine code or object code.
Matrix: A two-dimensional rectangle with row and column values.
Memory: Storage locations inside the computer. ROM and RAM are two different
types of memory.
Memory Location: A specific storage address in the computer. There are 131,072
memory locations (0-131,071) in the Commodore 128.
MFM: The abbreviation for Modified Frequency Modulation, a method of storing
information on disks. The 1571 disk drives can read and write to MFM disks.
Microprocessor: A CPU that is contained on a single integrated circuit (IC). Micropro-
cessors used in Commodore personal computers include the 6510, the 8502 and
the Z80.
Mode: A state of operation.