Athough I feel that the work done on DSZ and ZMODEM is exceptional,
I feel personally irritated by the ego of the author and his multi-page
opening diatribe on the futility of modifying or otherwise reverse engineering
DSZ. With that thought in mind I present two simple fixes to remove the
commercials from DSZ. These fixes will only work on version 060788--

Using debug or some similar program--

change byte 0888h from 75h to 74h--
this will remove the opening commercial.

change byte AE12h from 59h to 00h
change byte AE13h from 6fh to 00h
this will remove the closing commercial.

For those who are curious--the byte (yes, only ONE byte) that will enable
all the features (psuedo-registration) lies between the two addresses above.
I found it just to see if it could be done, I'll leave you to do the same.