IBM 5170 Technical Reference page 434

short circuit. A low-resistance path through which current flows,
rather than through a component or circuit.
signal. A variation of a physical quantity, used to convey data.
sink.. A device or circuit into which current drains.
software. (1) Computer programs, procedures, and rules
concerned with the operation of a data processing system.
(2)
Contrast with hardware.
source. The origin of a signal or electrical energy.
square wave. An alternating or pulsating current or voltage whose
waveshape is square.
square wave generator. A signal generator delivering an output
signal having a square waveform.
ss.
Start-stop.
start bit.
(1)
A signal to a receiving mechanism to get ready to
receive data or perform a function.
(2)
In a start-stop system, a
signal preceding a character or block that prepares the receiving
device for the reception of the code elements.
start-of-text
(STX).
A transmission control character that
precedes a text and may be used to ternlinate the message
heading.
start-stop system. A data transmission system in which each
character is preceded by a start bit and is followed by a stop bit.
start-stop
(SS)
transmission.
(1)
Asynchronous transmission such
that a group of signals representing a character is preceded by a
start bit and followed by a stop bit.
(2)
Asynchronous
transmission in which a group of bits is preceded by a start bit
that prepares the receiving mechanism for the reception and
registration of a character and is followed by at least one stop bit
that enables the receiving mechanism to come to an idle condition
pending the reception of the next character.
Glossary-32