To: V.29 9600 baud work group
From: Jeff King WB8WKA @WA8OOH.MI
RE: TNC compatibility


       TNC COMPATIBILITY WITH YAMAHA V.29 (fax) 9600 BAUD PACKET MODEM

Over the last few weeks, I have collected numerous schematics of various 
manufacturers TNC's. I wish to thank everyone who sent me schematics for
your help. First the good news.

This modem requires that the TNC have the ability to sync to a external
clock signal. By and large, the majority of TNC designs, including some
of the cheapest, will function in this mode. 

Now the bad news. If you own a Kantronics TNC, (besides the Data Engine)
this modem will not work. While I had known that it might be tricky to
externally clock the Kantronics TNC's, what I hadn't counted on was the
slowness of the "software HDLC" implemented in it. I spent some time on
the telephone with Kantronics, and learned that there TNC's will not
function past about 3000 baud. Apparently in the new design of "Data Engine"
they saw the shortcomings of the "software HDLC" and now have a hardware
HDLC implemented. If you have any high speed packet plans, I'd recommend
staying away from the older Kantronics (KPC-1, KPC-2, KPC-4, KAM) and going
with the "Data Engine", assuming of course you wish to go with a Kantronics
product!

Please note that not all these TNC's have actually been tested, but have
been determined to work based on the schematic/and or conversations with 
the manufacture. Units marked with a "*" have been confirmed through actual
testing to work with the modem design.

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  YAMAHA V.29 (fax) 9600 bps PACKET modem compatibility chart
 

If listed TNC appears to be able to work (see notes)
* = tested and confirmed


AEA:

 PK-232
 PK-80 *
 PK-88
 PS-186

AIWA:

 TNC2 clone


ASHBY:

 Not confirmed

C-64 DIGICOM
 I doubt it, but willing to try it someone has one.

DRSI:

 PCPA *  (All versions ASSUMING software can implement external clock)

GLB:

 TNC2A *
 GLB1  Not sure

HAPN:

 PC plug in card

HEATHKIT:

 HD-4040 *
 HK-232
 Pocket Packet (I think it will work)

KANTRONICS:

 Data Engine
 (NOTE: will NOT work on KPC-1, KPC-2, KPC-4, KAM

K3MC Awesome I/O:
 My guess is yes, but what EVER HAPPENED TO this card??

MFJ:

1270 *
1274 *
1278

PACCOMM:

 TNC220 *
 TNC2 clones *
 Tiny Two

TAPR

 TNC1*
 TNC2*
 NNC

TPRS/TEXNET
 NCP

VANCOVER 
 Not sure


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