🚀 go-pugleaf

I've seen nothing like this, particularly for Modula-2. There is (used to 
be?) a product called Disk Explorer from Quaid Software that discussed 
this sort of thing, but mostly this was a utility to allow one to do 
peculiar things to discs and it did not include any linkable code.

Mark Morgan Lloyd
mark_tbu@cix.compulink.co.uk

[Opinions above are the author's, not those of his employers or 
colleagues]

Charl Gerber (gerber@stb.dfs.co.za) wrote:
: I am looking for some documentation (preferable a www site) which describes
: some good methods of copy right protection in software. If possible, Modula
: 2 source code or libraries would even be better. Please send e-mail if you
: can help me.

I don't know if this is what you're looking for but I have a C library (no
source) that allows you to check the CRC and file length inside the program.
This is one way to check for reverse engineering and tampering (someone
disassembles the program to by-pass password/copy protection.)  It involves
calling a function at the beginning of the program that reads a section of the
executable with a stored CRC and file length.  It then calculates the CRC
of the executable and checks the file length with the stored values and reports
the results.  Then you add code to react on the results, ie. terminate the
program if they don't match exactly.  
This is very simple but using the C libraries with Modula-2 could be a 
problem, depending on what compiler you have.

Jeff

-- 
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> Hi,
> 
> I am looking for some documentation (preferable a www site) which 
> describes
> some good methods of copy right protection in software. If possible, 
> Modula
> 2 source code or libraries would even be better. Please send e-mail if 
> you
> can help me.
> 
> Cheers
> Charl Gerber                                  gerber@stb.dfs.co.za
> --
> South African Soccer Web Page : http://www.infostar.no/soccer/

Re copy protection....

tell us what you want to do - tie a piece of software to 1 computer, fix 
floppies so they can't be copied, or what? Are you selling 10 copies or 
100,000?

David