I/O port
Input/output port. The location on a PTC where
RS-232-compatible accessories are attached. Also, the
point through which the PTC sends and receives
transmission signals.
keyboard overlay
The plastic label that lies on top of the PTC keyboard,
identifying the function key definitions.
laser scanner
A type of bar-code reader that uses a beam of laser
light.
LCD
Liquid crystal display.
LED
Light-emitting diode.
mAh
Milliampere hour(s). A measurement of the ability to
provide electrical power.
modem
Modulator-demodulator. A communication device that
converts serial digital data from a transmitting device
to a signal suitable for transmission over a telephone
line and then reconverts the signal to serial digital
data for the receiving device.
MS-DOS
Microsoft Disk Operating System.
one-way
communication
Transport of information from one device to another
without interruption. In one-way communication, the
receiving device cannot respond directly to the
sending device.
prompt
Messages shown by the PTC that guide the operator
through the steps of the application program.
Prompts are different for different programs.
PTC
Portable Tele-Transaction Computer. A programmable
device used to collect, store, and transmit data.
RAM
Random access memory. In a PTC, RAM chips store
the program files and data entered by the operator.
RF
Radio frequency.
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