[comp.sys.mac.comm] CRC Header problems with ZTerm

dirty@engin.umich.edu (Cameron Javad Esfahani) (06/20/91)

I hope someone can help me with ZTerm.  I am using a TelePort 2400 baud
modem with MNP4 error correction.  In the documentation to TelePort it
says that I can increase my thoroughput by using a protocol that has no
built in error correction and let MNP4 take care of it.  I have
been trying to use ZTerm but every time I try to download a file I get
CRC Header errors and the program retries about 20 times then gives up!
I don't want to have to use kermit the rest of my life.  What do I
need to type on the unix side.  Does it matter which version of zmodem
I use?  It compiles okay and as far as I can tell, I am setting the
correct switches...
   
  Cameron Esfahani  (dirty@caen.engin.umich.edu)

johnston@minnie.me.udel.edu (06/20/91)

In article <1991Jun19.234823.9232@terminator.cc.umich.edu>, dirty@engin.umich.edu (Cameron Javad Esfahani) writes...
>I hope someone can help me with ZTerm.  I am using a TelePort 2400 baud
>modem with MNP4 error correction.  In the documentation to TelePort it
>says that I can increase my thoroughput by using a protocol that has no
>built in error correction and let MNP4 take care of it.  I have
>been trying to use ZTerm but every time I try to download a file I get
>CRC Header errors and the program retries about 20 times then gives up!
>I don't want to have to use kermit the rest of my life.  What do I

I have a similar question.  I just got a Teleport ADB modem which
supports MNP 4 and 5.  I notice an improvement when reading text
or news, but when I'm downloading I see little differnce in throughput.

Without MNP, zmodem gives 95-100% efficiency consistently.  When I
log in with MNP and hardware handshaking, retries and errors soak
up most of the through-put;  I get the same 220-240 cps for downloads.

I used to use kermit, so zmodem seems like a godsend.  However, MNP 
doesn't seem to be much of a bonus.  Am I missing something?

-- Bill (johnston@minnie.me.udel.edu)