Re: How to prevent My AppleSoft Basic Program Listing

[Benoit0123 <bgilon@free.fr>]

mhwordwriter wrote:
> hello i've written an applesoft basic game that uses shape table, .ml and
> .scrn I have the game fulling working but the einstein or tasc compiler
> doesn't work with it. How can I prevent someone from listing my code by
> typing list?
> any help is much appreciated
>
Applesoft has an internal "protection mechanism" which consists of setting
bit 7 of page zero location $D6 (mnemonic LOCK). When this bit is set, any
attempt to enter a command on the input line is interpreted as a RUN command
whatever the command is. Now, what could be a convenient way of setting this
bit as soon as the DOS loads the Applesoft file into RAM memory apart from
the obvious but weak method of setting this bit upon program init (and
hoping taht the program was RUNned directly from DOS instead of being loaded
then run in two steps).

HTHATS,
Benoît