Epson Multi-mode Data Controller MFJ-1278B - Manual (Page 357)

MFJ-1278B MULTI-MODE APPENDIX G: JUMPER FUNCTIONS
Table G-1: Jumper Function (Cont.)
Jumper # Position Function
JMP18 Pin 1 & 2 (default) Enable 19.2K baud termial
Disable 300 baud terminal
Pin 2 & 3 Enable 300 baud termial
Disable 19.2K baud terminal
JMP19 Outside pair (default) Enable 32K mailbox RAM
Middle pair Enable 128K mailbox RAM
Inside pair Enable 512K mailbox RAM
JMP20 ON 512K mailbox RAM installed
OFF (default) 32K or 128K mailbox RAM
JMP21 Pin 1 & 2 154 KHz to multi-level PCB
Pin 2 & 3 (default) 307 KHz to multi-level PCB
JMP22 Pin 1 & 2 Enable CW Grid Block Keying
Pin 2 & 3 (default) Enable CW Direct Keying
JMP23* ON Enable memory RESET
OFF (default) Normal operation
JMP25 Pin 1 & 2 (default) Normal Demodulator operation
Pin 2 & 3 Demodulator Bypass
JMP26** Pin 1 & 2 (default) Normal +5Vb bbRAM operation
Pin 2 & 3 Real-time clock installed
JMPA ON Disable multi-gray levels PCB
OFF (default) Enable multi-gray levels PCB
JMPB ON (default) On board transmit low tone
OFF out board transmit low tone
JMPC ON Enable external DCD
OFF (default) Disable external DCD
JMPD NOT used
JMPE*** ON (default) Disable Low Tone RTTY Demod
OFF Enable Low Tone RTTY Demod