Hi,
With 16 bits FP it was easy to use load and call functions + asm routines. However VFP dropped support for binary routines. In 32 bit windows, all lowlevel calls directly to hardware are masked by win kernel and therefore you need virtual device drivers to overcome it which is rather complex if you're not an experienced lowlevel programmer. If protection is based on port accesses it's allowable and not complex.
OTOH there is another simple way to make a simple protection in pure FP. Protection idea is based on the fact that each file occupies n clusters which is a multipl of 512. So with some static files, it means you have space to hide your own hooks. ie: You choose mysettings.ini file which is 608 bytes long. It allocates at least one cluster on the system and thus at least 1024-608 bytes are available to you. You simply put your hooks using lowlevel functions of FP.
Tekin