Xref: utzoo comp.binaries.ibm.pc.d:1665 comp.sys.ibm.pc:22722
Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!mailrus!iuvax!bobmon
From: bobmon@iuvax.cs.indiana.edu (RAMontante)
Newsgroups: comp.binaries.ibm.pc.d,comp.sys.ibm.pc
Subject: Re: DSZ rz & sz
Message-ID: <16127@iuvax.cs.indiana.edu>
Date: 3 Jan 89 19:53:05 GMT
Reply-To: bobmon@iuvax.UUCP (RAMontante)
Distribution: na
Organization: malkaryotic
Lines: 31

julian@uhccux.uhcc.hawaii.edu (Julian Cowley) writes:
-In article <54@VAX1.CC.UAKRON.EDU> Gregg Thompson writes:
->	Now how does one get rz and sz on Unixand dsz sz & rz to work at
->1024 blocks??  On bulliten boards I can upload and download at 1024 blocks
->just using standard commands with dsz (dsz rz and dsz sz), but when it comes
->to the Unix system it doesn't send or receive at 1024 characters a block!?!?!
->Ideas???
-
-Actually, the block size you are referring to is known as the
-subpacket size, because the subpacket may or may not elicit a
-response from the receiver, unlike an X/Ymodem block which always
-elicits a response.  [ rest deleted ]

Simtel20 has a 12/20/88 version of DSZ; the following excerpt from its
documentation may shed some light on this issue:

     Recent update history:

     12-20-88 A side effect of some optimizations to deal with PC Pursuit
     buffering problems caused 2400 bps transfers to use 512 byte
     subpackets unless explicitly overridden or a ZMODEM window size was
     specified.  While this does not slow things down much, numerous
     questions from users who confuse ZMODEM subpacket length with XMODEM
     block length did slow things down.  So, yet another version.

     Further fixes to the "estimate" command; it now works.

     A confusing "Carrier Lost" message has been changed to the standard
     "No Carrier Detect" message which is explained in DSZ.DOC.

(Note:  I believe that ZMODEM window size is specified with the -L flag.)