SCS PTC-IIex, Manual

Page: 213 / 220

F Glossary
200
RTTY
R adio T ele TY pe.
Rx
Receive. Short name for receive.
RxD
Receive data. Short name for receiving data.
SNR
Signal Noise Ratio.
TAPR
Short name for the Tucson Amateur Packet-Radio Corporation located in
Tucson/Arizona (USA). The TAPR group was most responsible for the outline for the
AX.25 protocol for Packet-Radio and developed the first TNC (about 1983) and the
following standards like TNC2 (about 1985). Further information about TAPR are
available via Internet:
http://www.tapr.org
Terminal
Simple input/output device of the early beginning of the computer area. A terminal
offers a serial interface, a screen and a keyboard. All signals received by the serial
interface are displayed on the screen. All inputs made at the keyboard are transmitted
via the serial interface.
TTL
Transceiver Transistor Logic. Integrated circuits completely built up using transistors.
TTL-level
Logic level used in TTL circuits. Usually 0V for a logical 0 (low), and +5V for a
logical 1 (high) are used.
Tx
Short name for transmit.
TxD
Short name for transmit data.
Version number
Each device has its on version number. The BIOS, the Firmware, PlusTerm,
PTCFAX, the manual and the other system utilities. Perhaps you will ask why,
because you are confused about the many version numbers. But it is easy to
understand: Without this numbers how would it be possible to differentiate between
old and new versions of the single parts?