[aprssig] MFJ Fill-In Digi setup
Stephen H. Smith
wa8lmf2 at aol.com
Thu Feb 19 23:18:12 CST 2009
Clay Melhorn wrote:
> Hello Cap,
> Sounds great, most of the time the digi will run stand alone tnc. I
> need to know if once the replacement chip is installed will the tnc
> still work with UIView32 from my PC when I need to monitor the local
> traffic and mapping? If that is the case I will send away for the chip.
1) You don't "send away" for the chip. You edit the UIdigi overlay
text file with your personal data (callsign, coordinates, beacon
messages and intervals, etc), merge this (using a special UIdigi
utility) with the binary file containing the actual digi program, and
then program the modified binary file into a 27256 or 27512 eprom
Or ask for the help of someone, like myself, that has an eprom
programmer device that will do eproms for others.
One real advantage of UIdigi is that your personalized settings
(callsign, beacon texts & intervals, lat/long, symbol codes, etc are
literally "frozen in stone" in the eprom firmware. Because of this,
your settings don't get lost with power failures, accidental resets,
dead backup batteries, etc.
2) UIdigi does not provide normal TNC operation -- it is solely a
stand-alone dedicated digipeater. I have been hoping for years that
the author might at least incorporate receive-only operation; ie echo
whatever the digi hears out the serial port. I brought this up on the
UIdigi mailing list about 8 years ago. Unfortunately, further
development of UIdigi seems to have ceased.
One approach is to make a "double-decker" eprom. Either UIdigi or the
original firmware occupies a 27256 eprom. You can use a 27512 (twice as
large) and place the OEM firmware in one half and UIdigi in the other.
When you insert the 24-pin eprom into the socket, bend pin 1 so it
misses the socket. Then wire a single pole double-throw toggle
switch to this pin so you can either ground pin 1 or connect it to +5
With the switch in one position, the original fimware is active for use
with UIview. Flip the switch the other way, cycle the power off and
back on, and the stand-alone UIdigi mode is enabled.
Stephen H. Smith wa8lmf (at) aol.com
EchoLink Node: WA8LMF or 14400 [Think bottom of the 2M band]
Home Page: http://wa8lmf.com --OR-- http://wa8lmf.net
World Digipeater Map
JavAPRS Filter Port 14580 Guide
"APRS 101" Explanation of APRS Path Selection & Digipeating
Updated "Rev H" APRS http://wa8lmf.net/aprs
Symbols Set for UI-View,
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