Msg: 5595 *Conference*

12-23-94 11:34:36

From: RON WIESEN

To : HOWARD KRAUS

Subj: REPLY TO MSG #5592 (MODEL 100 QUESTIONS)

Looks dismal Howard.  I'm an Amateur (WD8PNL) but I'm not a packeteer and I
haunt the HF bands on CW and RTTY modes.  But I've caught some cross traffic
concerning use of the M100 with TNCs.  As I understand them, TNCs come in two
flavors: dumb and intelligent.  The intelligent TNCs need only dumb terminals
so the M100 with TELCOM does fine.  But a dumb TNC needs an intelligent host so
the M100 must have a TNC program.
 
Many have asked about M100 TNC programs, but to my knowledge nobody has made a
commitment to develop one.  It appears technically possible and if anyone had
done it I'm sure word would have spread like wildfire and COMPUSERVE and this
board would have the good news quickly.
 
Concerning your TNC by MFJ, if my memory serves me correctly the Model MFJ-1274
is just a dumb Frequency Shift Keying (FSK) modem which MFJ aligned for CW,
RTTY, and AMTOR service.  The model I remember used analog electronics for its
baseband carrier oscillators and with the trim pots you can realign them for
dang near and FSK deviation.  So I guess you have done this (if needed for
packet) but both the MFJ-1274 and the M100 are dumb so there's no packet
intelligence in your setup.  Again, I'm not a packeteer but I'm going from
memory here.
 
As far as having date freeze, why should it change?  Did midnight elapse?  If
the M100 has time freeze, then I suspect its interrupt system is staying
disabled for some reason or that it's so occupied (TELCOM?) it has no time for
such trivia.  Sorry I can't offer a better explanation but I don't understand
why the date or time is visible if in fact you are using TELCOM.  If you're not
using TELCOM for dumb terminal operation, than what intelligentrogram do you
have running in the M100?
 
I can help with the shielded printer cable.  I make them with ribbon cable,
folded once and sheithed in 1/2 inch braid.  A 2-turn (goes through center
twice, but around just once) ferrite load at the printer end seems to help keep
things very RFI quiet.  Radio Shack's square ferrite (split in two halves)
block fits snugly and develops enough inductance to choke off any noise current
on the outside surface of the braid.  Works for me, but the computer end
connector is not generally available so I have a source if you need one.
 
About the buffer you mentioned, I don't follow the logic at all.  Sorry.
 
Merry Christmas and 73