Linux-Hams archive - May 1997: Multi-drop kiss / TNC2s

Multi-drop kiss / TNC2s

Mike Bilow ()
Mon, 26 May 97 15:28:00 -0000


Phil Maley wrote in a message to Mike Bilow:

PM> Has anyone got multiple TNC2s running in multi-drop kiss
PM> mode from a single serial port? I am trying to set this up
PM> using the BPQKISS eprom images which each have a unique
PM> address byte at address 20h.

PM> My setup works fine with a JKISS image and kissattaching the
PM> hardware directly. It also works with a KPC9612 using mkiss
PM> and kissattaching the resulting virtual TNCs. However when
PM> I try a BPQKISS rom in the TNC2, with mkiss, I can get linux
PM> to transmit but it hears nothing from the TNC.

When you say "multiple," do you mean more than two? Forgive me for asking the
obvious question, but have you checked the handshake lines? It may be that the
BPQ firmware honors them and the other implementations do not.

I see that Tomi has already mentioned checksumming and polling. However, since
these were BPQ innovations in the first place, I believe that the firmware will
only go into polling mode when requested by the master. Karl Medcalf, WK5M, of
Kantronics wrote a fairly thorough explanation of the BPQ firmware enhancements
to KISS in one of the CNC Proceedings a few years ago.

-- Mike