Occasionally, Apple receives requests from developers who want to modify
Apple File Exchange code. Usually, these people want to support serial
connections to non-standard devices. Unfortunately, it would not be
practical to try modifying AFE.
However, if you're interested in writing translators for AFE, see APDA's
"Apple File Exchange Technical Reference Package v.1.1". This package
includes one 800K Macintosh disk and 184 pages of documentation. For
details, search the Tech Info Library under "APDA".