The Packet Radio
“
2 N 1
”
Handbook
by
Buck Rogers
K4ABT
Section 1
;
Packet Radio “The Basics
”
Section 2
;
The X1J4 System Node Operator’s (SNO) Handbook
Section II
;
TheNET X1J4 System Node Operators Handbook
__ Page 37
Chapter 16 Section II
GATEWAY INTERFACING & SETUP:
(NOTE: T
his modification does not apply to TNC2’s or clones manufactured after July 1990)! (see the illustration of this
modification in the illustrations at the back of this handbook).
The following modification is required for TNCs that will be used in dual-or multi-frequency TheNET
X1
configurations.
Since it does not impair normal operation in any way, we recommend it for all TNCs to be used with TheNET
X1
. You may
want to upgrade to dual-frequency operation later.
To make this modification, connect one end of a wire to pin 23 of the RS232 connector. Connect the other end of the wire
to pins 1-2-3 of JMP9 (these three pins are already hooked together on the circuit board).
This modification allows the TheNET
X1
firmware to be configured for multi-frequency operation by jumping RS232 pins
10 and 23 together in the TNC-to-TNC cable.
SET BAUD RATE SWITCHES:
Follow the switch-setting instructions in the TNC2 manual. I have performed extensive reliability testing of TheNET
X1
at
HDLC and RS232 baud rates up to 9600; it runs reliably at these high baud rates even at slow CPU clock speed.
For dual- or multi-frequency operation, I suggest setting the RS232 speed at 9600 baud (or the highest RS-232 port baudrate
i.e.; 19,200 baud’s for MFJ-1270"C") it makes a big difference in cross-frequency performance!
WIRE TNC-TO-TERMINAL CABLE:
To connect a host terminal to the TNC2, almost any standard RS232 cable will do (as long as pins 9, 10, and 23 are not
used).
CONFIRM TNC/NODE OPERATION:
Install the
X1
EPROM; If you have the add-on DEViation PC board, install it while the TNC is open. Connect a terminal
to the TNC, power it up, and make sure that you get a sign-on message and that the unit still appears OK. Note the
STA
tus
LED should glow at half brilliance when compared to the other LEDS.
If it doesn't:
(1)
You have made an error.
(2)
You have installed a bad EPROM.
(3)
Your TNC won't run at the fast CPU clock speed.
(4)
HAVE YOU INSTALLED THE WIRE FROM PIN ONE (1) OF THE
X1
EPROM TO PIN 8
OF THE MODEM HEADER?
NOTE
: Step number 4 does not apply when using MFJ-1270”C” REV 11 or above!