Apple Express Fax/Modem - Manual (Page 172)

H
half-duplex (1) A setting causing characters that you enter on your computer
to be echoed not from a remote system but on your screen. (2) A two-wire
circuit designed for communications in either direction but not both
directions simultaneously.
handshaking A protocol for devices to exchange information about the
communications connection itself, such as when to start and stop transmitting.
hertz The unit of frequency measurement. For example, 1 hertz equals 1
cycle per second. Abbreviated Hz.
hexadecimal The representation of numbers in terms of powers of 16, using
the digits 0 through 9 and the letters A through F. Hexadecimal numbers are
easier for people to read and understand than binary numbers but can be
converted easily and directly to binary form. Each hexadecimal digit
corresponds to a sequence of four binary digits, or bits.
host computer The Macintosh in which your modem is installed.
I
input (1) Information transferred into a computer from some external source,
such as the keyboard, a disk drive, or a modem. (2) The act or process of
transferring such information.
integrated circuit An electronic component consisting of many circuit
elements fabricated on a single piece of semiconducting material, such as
silicon.
interface The devices, rules, or conventions by which one component of a
system communicates with another.
I/O Input/output; the transfer of information into and out of a computer.
See also input.
160 G L O S S A R Y