Dick, Squeeze and Unsqueeze manage a data compression alogrithm that
generally will reduce the size of a text file by about 30%-40% or so. These
originated with CP/M (maybe even earlier) and are effective for modem
transfer of source files (cuts down transmission time) and for archival of
source files on your own disks (even with 880K its still useful). Both
programs are available here in source and executable form. The problem you
may be having with your executable downloads is a disagreement between XMODEM
and AmigaDOS. AmigaDOS expects only the original executable file to be run,
but XMODEM will only download even number of blocks, resulting in padding
added to the end of the executable file, which AmigaDOS doesn't like. Thus,
you can use the CHOP program, avaliable here in various flavors, to restore
the file to its original length. I believe a new version of ATerm is about
that will do this automatically, once you get this ATerm.