[aprssig] What is "TNC Channel Switching"?

Stephen H. Smith wa8lmf2 at aol.com
Sat Apr 12 16:37:02 CDT 2014

On 4/12/2014 1:55 PM, Greg D wrote:
> Stephen H. Smith wrote:
>> However, many users still use the command-line mode instead, since many older
>> TNCs don't support KISS.   (Particularly the MFJ 127x series TNCs that
>> crammed in numerous other modes, so that there wasn't enough room in the
>> 27256 eprom for KISS support.  I have replaced the OEM firmware on countless
>> MFJ 127x TNCs with the final release "official" TAPR 1.1.9 firmware precisely
>> to regain the KISS capabilities.)
> Um, I have an MFJ 1278T TNC, and am running it in KISS mode under APRSIS/32.
> Stock firmware on it, I believe, though I don't recall what version.
> Greg  KO6TH

That's a relatively late version of the MFJ-1270 family that (I think) finally 
went to 27512 EPROMs instead the '256s of earlier versions and consequently has 
a lot more room for code.

The original MFJ-1270 and the MFJ-1274 that I still have came OEM with 
KISS-less firmware.    I put the generic last-ever TAPR TNC2 V1.1.9 firmware in 
both instead, to regain the KISS mode.

(I also hacked the eprom image to make the device power up defaulted to full 
8-bit 8-N-1 instead of the archaic default 7-E-1 serial port settings, avoiding 
having to constantly init with AWLEN 8, 8BITCONV OFF and PARITY 0.)



Stephen H. Smith    wa8lmf (at) aol.com
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