Along similar lines, the shareware assembler A86 watermarked the binaries it produced, so that unauthorised use of unregistered copies could be proven. It did t

Along similar lines, the shareware assembler A86 watermarked the binaries it produced, so that unauthorised use of unregistered copies could be proven. It did this by - or so it was claimed - choosing one specific instruction over another, when it had a choice: http://www.preterhuman.net/texts/computing/general/DOCUMENTATION/a01.txt http://www.preterhuman.net/texts/computing/general/DOCUMENTA... (see section 6)