-.I nbytes
-bytes pointed to by
-.I from
-to the position pointed to by
-.I to,
-exchanging adjacent even and odd bytes.
-It is useful for carrying binary data between
-PDP11's and other machines.
-.I Nbytes
+.I len
+bytes from the location referenced by
+.I src
+to the location referenced by
+.IR dst ,
+swapping adjacent bytes.
+.PP
+.I Len