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- From: swalton@solaria.csun.edu (Stephen Walton)
- Newsgroups: comp.sys.amiga.announce
- Subject: XPR Kermit 1.111 available for ftp
- Message-ID: <11298@ucdavis.ucdavis.edu>
- Date: 29 Feb 92 21:21:11 GMT
- Sender: usenet@ucdavis.ucdavis.edu
- Reply-To: swalton@solaria.csun.edu (Stephen Walton)
- Followup-To: comp.sys.amiga.datacomm
- Lines: 67
- Approved: zerkle@cs.ucdavis.edu
-
- I have released version 1.111 of my XPR Kermit library to the world.
- At present, it is available for anonymous FTP from ab20.larc.nasa.gov
- as file xprkermit-1.111.lzh in the /amiga/datacomm directory. Please
- feel free to FTP it from ab20 and repost it wherever you please,
- including FTP sites in Europe, Asia, and Australia, the commercial
- services, and your local BBS's.
-
- For the new to the net, a brief introduction: Kermit is a file
- transfer protocol (yes, named for the frog) invented at Columbia
- University in the late 1970's. Its advantages over the other
- protocols currently in use are many, including: the ability to
- transfer binary files over 7-bit-wide data paths with or without
- parity; better handling of poor quality lines (in my experience); the
- fact that packets contain no control characters other than the
- start-of-packet and end-of-packet markers, easing transmission over
- various networks; support of flow control as a natural part of the
- protocol (since control-S and control-Q will never be part of a
- packet); and three types of transmission integrity checking (block
- checks) which have different tradeoffs between speed and reliability.
-
- XPR Kermit is an implementation of the Kermit protocol as described
- above in the form of an eXternal PRotocol (XPR) library. This means
- that, once one copies the file xprkermit.library to one's LIBS:
- directory, that all communication programs which support external
- protocols have automatic access to the features of XPR Kermit. A
- partial list of such programs is: VLT (freeware), NComm, JRcomm, Term
- 1.9, and Handshake (shareware), and A-Talk III (commercial). The
- advantage of this scheme is that you need not upgrade your terminal
- program to upgrade the file transfer protocols it uses! Also, because
- XPR's are implemented as Amiga shared libraries, multiple copies of
- terminal programs can share the same copy of the protocol code,
- reducing the amount of memory needed for simultaneous transfers.
-
- In version 1.111, I have fixed several bugs in XPR Kermit 1.5, the
- previous release, and added a few new features. The biggest new feature
- is that the library is now re-entrant, meaning that multiple XPR
- Kermit transfers can happen at the same time. The biggest bug fixed
- was a buffer overflow problem that often prevented XPR Kermit V1.5 from
- working at all on A3000 class machines.
-
- Thanks at this point go to my beta testers, especially Willy Langeveld
- and Marvin Weinstein of SLAC, Torkel Lodberg (author of NComm) and Bob
- Laughlin.
-
- Version 1.111 of XPR Kermit is not the same as the beta version of C
- Kermit recently announced on comp.sys.amiga.datacomm. I am the
- co-author of XPR Kermit, and Amiga maintainer of both it and C Kermit,
- but the codes are presently separate. (Amiga C Kermit is a standalone
- executable program.) Now that Amiga C Kermit is in beta in a stable
- form, I am looking at the possibility of turning the C Kermit code
- into the next version of XPR Kermit. This would be a *major* upgrade
- in XPR Kermit capabilities, including: attribute packets, which tell
- the receiver what the file date/time/size/access mode/record
- length/record format/etc. of the received file is; extra long packets,
- up to 9000 bytes; and sliding windows, an extension to Kermit which
- allows continuous sending of packets, thus using 100% of the available
- bandwidth. However, these new features come at a fairly high price in
- terms of code size and complexity, and may not be suitable for an XPR
- library.
- -----------
- Stephen Walton, Dept. of Physics & Astronomy, Cal State Univ. Northridge
- srw@csun.edu or swalton@solar.stanford.edu
-
- --
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