CHRONOLOGY OF FILE-TRANSFER PROTOCOLS IN PUBLIC DOMAIN.


** Extracted from an article in PC WEEK, Sept. 8, 1987, by Don Steinberg.


    1977 - XMODEM:

        Hobbyist Ward Christensen developed the MODEM.ASM protocol as a way to
let his CP/M microcomputer trade files with other systems.  He placed the
protocol into the public domain by submitting it to a CP/M user's group,
where others refined it and renamed it XMODEM.
        As the first error-correcting protocol for microcomputers, XMODEM saw
wide use and was implemented in DOS programs when IBM PCs arose.


    1981 - Kermit:

        Frank da Cruz and Bill Catchings of Columbia University developed the
Kermit protocol as a means of letting diverse computer systems on campus
exchange files.
        Users have since written versions of Kermit for numerous new computer
systems.  Kermit now is available for about 230 different machines and
operating systems.
        Most uses of Kermit, along with source code, are available from
Columbia's Center for Computing Activities in New York for a shipping and
handling fee.


    1985 - X.PC:

        Tymnet/McDonnell Douglas Network Systems developed X.PC primarily to
facilitate transfer over its Tymnet value-added network.  Designed to be
similar in structure to the established X.25 protocol for transmission
within packet networks, X.PC provides an error-checked interface between
user equipment and such networks.  As a link-level protocol, it does not
incorporate file-handling features such as those used in XMODEM and Kermit.
        The protocol is available for a requested $20 donation to the X.PC
Vendor/User Forum, which may be reached through Tymnet.


    1986 - MNP:

        Microcom Inc. placed its Microcom Network Protocol (MNP), which it had
been licensing to developers since 1982, into the public domain in 1986.
        As a link-level protocol, MNP doesn't incorporate file-handling
features such as those used in XMODEM and Kermit.  It is most often
implemented in error-correcting modems.
        Currently, MNP Classes 1-4 are available for free, while newer layers 5
and 6 are available from Microcom for a $2,500 licensing fee.


    1986 - FAST:

        Written by programmers at Hayes, FAST is a simple file-transfer
protocol with no error correction.  It is designed for use on error-free
links such as those offered by X.PC, MNP and X.25 networks.  The FAST
specification is available from Hayes, while implementations are available
in a few commercial programs.