Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!ken
From: ken@cs.rochester.edu (Ken Yap)
Newsgroups: comp.lang.pascal
Subject: Re: xmodem help needed
Message-ID: <1989Mar1.015140.7134@cs.rochester.edu>
Date: 1 Mar 89 06:51:40 GMT
References: <401@advdev.Cambridge.NCR.COM> <14800@cup.portal.com> <15068@cup.portal.com> <8436@paris.ics.uci.edu>
Reply-To: ken@cs.rochester.edu (Ken Yap)
Followup-To: comp.protocols.misc
Distribution: usa
Organization: U of Rochester, CS Dept, Rochester, NY
Lines: 22

|>   Isn't it funny how everyone knows how to USE XModem and no one
|>knows how it works?  (Transfer protocols are the most closely guarded
|>secrets among programmers it seems)

There is no conspiracy involved. The protocol description is available
from various places. I have a copy somewhere in my pack rat directories.
And sources for various implementations are available too. (Source is
truth :-).) Of course, hardware tends to intimidate some software types.

|    It may be true of x-modem (which, actually, I don't know how to use) but
|    Kermit's protocol is extensively described in documentation available for
|    download from Columbia University.  I'd be interested in knowing whether
|    XModem is as secure a protocol as Kermit -- the brief descriptions I've
|    heard of it, compared with the description of Kermit, suggest that it isn't.

And the Kermit protocol is also described in a book.

By the way, I not sure what you mean by secure. Not as likely to
get into strange states? Less susceptible to data errors?

Now if you want something you use all the time but most people don't
understand, you have to look no further than your compiler.