Path: utzoo!attcan!uunet!lll-winken!ames!apple!rutgers!mcnc!ecsvax!kms
From: kms@ecsvax.UUCP (Ken Steele)
Newsgroups: comp.sys.amiga
Subject: Xmodem bug in VT100 2.8a?
Keywords: xmodem checksum receive routine
Message-ID: <7082@ecsvax.UUCP>
Date: 27 May 89 04:35:43 GMT
Organization: UNC Educational Computing Service
Lines: 26



There appears to be a bug in the xmodem checksum receive routine in
VT1002.8A.  The symptoms are described below.

The amiga is the receiver.  The sender is a SYM (a 6502 single
board).  If the SYM goes into it's send routine (basically
sitting there looking for a NAK before beginning transmission)
before the receive command is issued on the amiga, then the transfer
works. But if you start the receive on the amiga before starting the
send on the SYM then there is no transfer. There is no trouble like
this when using another program such as Comm1.34.

The problem seems to be that when receive is first started, a NAK is
sent out.  But NO other NAK's are sent out afterwards.  My
understanding of the xmodem protocol is that the receiver should
continue to send out NAKs periodically for a very long time, as the
sender is looking for that prior to sending the first block.

Has anyone run into this problem?  Or did I miss something?


-- 
Ken Steele   Dept. of Psychology    kms@ecsvax.[bitnet || UUCP]
             Mars Hill College      kms@ecsvax.uncecs.edu
             Mars Hill, NC 28754