Function 43 - input/output to a port.
Output data to port
Parameters:
- eax = 43 - function number
- bl = byte for output
- ecx = port number 0xnnnn (from 0 to 0xFFFF)
Returned value:
- eax = 0 - success
- eax = 1 - the thread has not reserved the selected port
Input data from port
Parameters:
- eax = 43 - function number
- ebx is ignored
- ecx = 0x8000nnnn, where nnnn = port number (from 0 to 0xFFFF)
Returned value:
- eax = 0 - success, thus ebx = entered byte
- eax = 1 - the thread has not reserved the selected port
Remarks:
- Previously the thread must reserve the selected port
for itself by function 46.
- Instead of call to this function it is better to use
processor instructions in/out - this is much
faster and a bit shorter and easier.