caf@omen.UUCP (05/20/86)
The ZMODEM protocol is described in ZMODEM.DOC, posted to net.sources. ZMODEM was developed to correct many of XMODEM's and YMODEM's shortcomings, especially with respect to packet switched networks and user interface. ZMODEM provides high performance with timesharing systems and networks, a simple user interface, security verification to protect from Trojan Horses, command download and other advanced protocol management functions. Unix/Xenix programs that implement ZMODEM as well as XMODEM and YMODEM have also been posted to net.sources. rz and sz supercede rb and sb. Because of careful attention to serial port I/O, these programs are less demanding of CPU resources than other XMODEM programs, especially UMODEM.