[Coco] Old Copy Protection Schemes

[Steve Ostrom]

Included in a recent eBay purchase of some Coco equipment was someone's 
backup disk containing three programs, including Blackbeard's Island, a 
graphic adventure marketed by Tom Mix and written by Greg Miller.  I 
made a copy of this disk, then ran Blackbeard's Island from the copy.  
There was an entertaining graphical intro of scrolling words on an old 
fashioned scroll, then the program quit at the same time as the floppy 
drive started and quickly stopped.

 I rebooted my Coco3 and checked the directory of the diskette and found 
the other two programs were still there but Blackbeard's Island was now 
gone.  This is the first time I have run into a self-destructing copy 
protection scheme.  I can't imagine this was common, but I think I 
remember Marty being very agitated about this type of copy protection 
especially.  Was this one of the only programs to utilize one of these 
"Mission Impossible" self-destructs?  Are there any details on how the 
program knows it is a copy?

-- Steve --