X/Y/Z Modem File Transfers
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University of Hawaii at Manoa College of Engineering |
These three file transferring methods are the preferred methods, due to their built-in error correction scheme. This means if there are any errors encountered while transferring a file, the computer will try to fix the error by having erroneous pieces of the file re-sent. These errors typically occur when there is some line noise, which could garble the characters, or in other instances, such as when your roommate or parent picks up the phone and DOESN'T kick you off.
ZModem Transfers
If your terminal emulator supports zmodem protocol, downloading (sending from Wiliki to your computer) file(s) is as simple as...
sz file1Most terminal emulators which support Zmodem automatically recognize that a file transfer has started, and will take over.
Note that you may specify more than one file name when transferring, as Zmodem supports batch transfers. Two options worth noting for Zmodem (and Xmodem, described below) are the -a and -b options, which can be specified right before the first file. The -a option is useful for transferring text files. Using this option will fix some of the carriage return and line feeds which may not transfer properly to your PC or Macintosh. The -b option is used to transfer binary files, such as executable programs.
To upload files (send files from your computer to Wiliki), your terminal program may need to be configured to send the right zmodem receive program. Otherwise, type "rz" first, and then initiate the transfer from the home computer.
Xmodem and Ymodem
An older but similar protocol, called X-modem does not support batch file transfers, but is more likely to be found on more terminal programs. To download a file, first type "sx filename" (by default, X modem uses binary transfers), and then use the "receive Xmodem" command on your terminal program to receive the file. To perform an upload to Wiliki, type "rx", followed by the file name to transfer the file.
The main difference between Xmodem and Ymodem is Ymodem's ability to send several files at once. Because Zmodem has a recovery feature that Ymodem lacks, Ymodem is not explained here.