I was just wandering if it is possible to use the asm commands 'in' and 'out' while programming for windows. I wanted to know if I can use them as a direct way to monitor keyboard input, but so far using either of them crashes my program.

Best to use them only in ring0 for win nt and winxp.

roticv is right.

Generally, every ring3 task has bit array that defines which ports it can access and which not. But i don't know how to get this list under windoze, but i think all ports are disallowed.

I/O instructions, like STI and CLI instructions, are "trusted", what means you can use them only if CPL<=IOPL. In fact, this condition is not true on most win systems, surely not on higher than 9x.
As vid said, there is additionally the bit array that defines which ports are not illegal when not CPL<=IOPL. Unfortunatelly, that array is located in TSS (task state segment) and is not accesible in ring3 at all.

If you use cygwin (a unix environment for win32) you may have to take a look at the link below, since they have developed a driver (named ioperm.sys) for supporting the well known ioperm() and iopl() functions, which you can change the privilege levels with.

http://openwince.sourceforge.net/ioperm/

Ãœdv.
Endre

Isn't it possible making a VXD file?

vxd works only on 9x, while .sys works on nt..

As I see you have the following opportunities:

1. Use of microsoft DDK (I guess this is the best if you want own DMA operations too)
2. Use of any hack-driver (like the mentioned ioperm.sys for cygwin). In this case you may still have to care about your virual address problem, since you can't see physical address from user-space, however devices need it for instance for DMA as well as for memory mapped IO (MMIO).
3. Change to any of the open-source unix systems. There you can use ioperm and iopl (they are sytem calls consequently interrupts) as root. Although the virtual/physical address problem is still standing, so you will be compelled to hack your kernel (for linux it is not so complicated.)
4. Use of DOS with any 32bit extender or you can write a little code to switch to 32bit flat-mode.

Did I give a miss something?

Ãœdv.
Endre

u forgot something but generaly O.K.
WinIo

Thanks, it seems to solve each above mentioned problem.