ZMODEM Preferred

ZMODEM is the preferred transfer method and you should use it wherever possible. The ZMODEM Driver implements most of the commonly used ZMODEM features, and is compatible with a wide range of host implementations.

Setting the Options

Black Night will normally encourage the host to use segmented streaming for maximum safety. However, if you're certain that hardware handshaking is working correctly, then you can turn this feature off (to improve efficiency), by unchecking the "Declare a Receive Buffer of" checkbox. However, in a really difficult environment, you should leave this box checked, and also instruct Black Night to escape all control characters instead of just the common ones.

Selecting any of these options will degrade the transfer efficiency, but will allow faster error recovery in a difficult environment. Typically you don't need to select these options if you are using hardware handshaking and error correcting modems. However, if you are a transiting a packet or telnet network, then you should probably narrow the window and escape all control characters.

Partial Download Recovery

If a ZMODEM download is closed before it completes, Black Night will create a partial download package file. This file contains everything received so far, as well as a description of the download session. Later, if you resume the session, Black Night will search the Receive Folder for a partial download package file that matches the new session. If it finds one, the session will resume where you left off.

Graceful Termination

Have you ever cancelled a ZMODEM session only to find that someone forgot to tell the host, leaving you with screens and screens of raw binary data to deal with. It used to happen to me all the time, so I've paid special attention to it.

So, if you cancel a ZMODEM session, Black Night will stay in control until the host has stopped sending data. In most cases, Black Night will detect the exact transition from file transfer to normal mode which means you won't get screens and screens of raw binary data; but you will still get the "Transfer Cancelled, Press any Key ..."  message from your host.