[aprssig] TNC-200 Assistance
Stephen H. Smith
wa8lmf2 at aol.com
Mon Jan 1 03:57:54 EST 2007
vk5jfk at activ8.net.au wrote:
> Should the DataBits be 8 and not 7
>
> Ben Lindner
> VK5JFK
>
Yes. 7-E-1 is an obsolete hangover from the mid 1970s when packet was
born. At that time, before personal computers, the dumb terminals and
Teletype machines widely used with minicomputers (and also with and
early TNCs) almost universally used 7 bits even parity. This was
before personal computing and binary files with 8-bit bytes. [Mass
storage was something you did with punched paper tape with 7 holes
across the width of the tape.] Somehow this configuration persists to
this day as the default setting in TNCs. For operation on APRS, you
want 8-bit transparency. For most TNC2 devices and similar, the TNC
init file needs to issue the commands
8BIT OFF (meaning don't mask incoming 8-bit bytes off to 7 bits)
AWLEN 8 (meaning use 8-bit long full bytes)
I have modified the final release of the official TAPR firmware (Ver
1.1.9) to power up in 8-N-1 instead of the original 7-E-1 mode which
makes it much more convenient for modern computer applications. A
binary file of this modified firmware, which can be used to program an
EPROM, is on my website at:
< http://wa8lmf.net/miscinfo/index.htm >
On this download page of miscellaneous files and reference sheets, look
for the file
TNC2-119b-8N1Mod.zip
As a added bonus, this release of the TNC2 firmware includes KISS mode,
and alsd the first (and last) explicit support for APRS in the form of a
dumb APRS tracker mode. From an attached terminal, you command the TNC
into the tracker mode, disconnect the terminal and then connect a
NMEA-format GPS to the serial port. The TNC will then transmit raw NMEA
strings over the air in a manner similar to the dumb tracker mode on a
KPC3.
Just above this item in my MISCINFO list is a quick hack I threw
together years ago in compiled Quickbasic (i.e. standalone .EXE) to send
the command sequence to get a TNC out of KISS mode. Look for
KISS_OFF.EXE
Rich Schiller wrote:
>
>
> Don;t know if this helps or not, but the serial number for the TNC is
> 27446. There are also labels, handwritten, on some of the e-proms,
> they are as follows:
>
> State 1.09
> WA4FLR-8 FAY
> TheNet 2.11 st
>
TheNet is a replacement EPROM for the standard TNC2-style firmware, to
use the TNC as a dedicated packet (not APRS!) digipeater. The TNC is
never going to function as a normal end-user unit with this firmware in
it. Remove this EPROM, erase it and reprogram it with the firmware I
describe above.
tim_cunningham at mindspring.com wrote:
> Rich,
>
> You must replace the TheNet EPROM with a TAPR EPROM, a Paccomm EPROM,
> or a KISS (JKISS) EPROM. The Paccomm EPROM v5.0 is still available
> from Pac-Comm at http://paccomm.com/
>
> The KISS EPROM would work best if you plan to use the TNC with any of
> the APRS software programs.
>
>
KISS mode will work with UI-View, APRSplus and Xastir. It WON'T
work with the original DOSaprs, APRSpoint or WinAPRS. (None of these
programs support KISS-mode operation.)
--
Stephen H. Smith wa8lmf (at) aol.com
EchoLink Node: 14400 [Think bottom of the 2M band]
Home Page: http://wa8lmf.com --OR-- http://wa8lmf.net
NEW! TNC Test CD
http://wa8lmf.net/TNCtest
JavAPRS Filter Port 14580 Guide
http://wa8lmf.net/aprs/JAVaprsFilters.htm
"APRS 101" Explanation of APRS Path Selection & Digipeating
http://wa8lmf.net/DigiPaths
Updated "Rev G" APRS http://wa8lmf.net/aprs
Symbols Set for UI-View,
UIpoint and APRSplus:
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