PK-88 OPERATING MANUAL
INTRODUCTION
1 - 2
PK-88 - 15
1.2.2
Modem Characteristics
Modulator/Demodulator:
AMD 7910 'World Chip' modem.
Data format:
Serial, asynchronous
Modem Tones:
Bell 103 and Bell 202
Transmitter:
Modulation method:
Binary, phase-coherent NRZI FSK
Frequency accuracy:
Bell 202 (mark) ± 1 Hz
All others (mark) ± 0.4 Hz
Harmonics:
45 dB below fundamental, single tone
Receiver:
Demodulation method:
Differential FM detection
Output Level:
5 to 100 millivolts RMS, adjustable by internal control
1.2.3
Processor System
Protocol conversion:
Zilog Z-80 microprocessor
RAM:
32 kilobytes
ROM:
Up to 48 kilobytes of ROM may be used
Hardware HDLC:
Zilog 8530 SCC
1.2.4
Input/Output Connections
Radio Interface:
Eight-pin microphone connector
Input/Output Lines
Receive audio
Transmit audio
Push-To-Talk (PTT)
External squelch input
Ground
External Modem Interface:
Pins 13 through 17 of Connector J1
TTL Input/Output Lines
Receive data (RXD)
Transmit data (TXD)
Transmit Clock (TXC)
Data Carrier Detect (DCD)
Ground
Terminal Interface:
Standard RS-232C 25-pin DB25 connector
Input/Output Lines
RS-232C (CCITT V.24/V.28) with full handshake (hard-
ware and software)
Terminal Data Rates
Auto-baud selection of 300, 1200, 2400, 4800, and
9600 BPS. TBAUD adds 45, 50, 57, 75, 100, 110, 150,
200, 600 and 19,200 BPS terminal rates.
1.2.5
Controls and Indicators
Front Panel Controls:
Power Switch
Status and Mode Indicators:
CONV, TRANS, CMD, SEND, DCD, STA, CON, MULT,
PWR
