The files in this directory (zmodem.txt and zmodem.h) should be
sufficient to write a completely new implementation of Zmodem. The
file zmodem.h is a subset of the zmodem.h file from rz/sz.c, which
has been placed in the public domain by Omen. The file zmodem.txt 
described the protocol; zmodem.h is there for the magic numbers
(mainly packet ID bytes).