and what hardware architecture, what mouse (USB, PS/2, serial, something else maybe).
I've done it 15 years or so ago. At the time we had to write our own mousedrivers, was fun.
I think the disk with that code is by now unreadable (not that it would do much good of course as hardware and operating systems have progressed rather a lot since).
you have to understand a little about assembly programming. REGS is just a union on some integers that the function int86() uses to set up the microprocessor's registers before executing the interrupt instruction. google for dos interrupts and you will find this among many others.
INT 5 - Print Screen
Does this do something like screen capture?
Because since my program is DOS based program none of the screen capture programs seem to work. And I need to show screen shots of my program in my project.