www.pudn.com > SJF2443.zip > ppt.c

#include  
#include  
#include  
#include "..\include\ppt.h" 
 
int validPpt;  
 
int GetValidPpt(void) 
{ 
	// search for valid parallel port 
	_outp(LPT1, 0x55); 
	if((int)_inp(LPT1) == 0x55) 
	    return LPT1; 
	 
	_outp(LPT2, 0x55); 
	if((int)_inp(LPT2) == 0x55) 
	    return LPT2; 
	 
	_outp(LPT3, 0x55); 
	if((int)_inp(LPT3) == 0x55) 
	    return LPT3; 
	 
	return 0;	 
} 
 
#define ECP_ECR		    (0x402) 
#define ECR_STANDARD	    (0x0) 
#define ECR_DISnERRORINT    (0x10) 
#define ECR_DISDMA	    (0x0) 
#define ECR_DISSVCINT	    (0x4) 
 
void SetPptCompMode(void) 
{ 
    //configure the parallel port at the compatibility mode. 
    _outp((unsigned short)(validPpt+ECP_ECR),ECR_STANDARD | ECR_DISnERRORINT | ECR_DISDMA | ECR_DISSVCINT); 
} 
 
int InstallGiveIo(void) 
{ 
    HANDLE h; 
    OSVERSIONINFO osvi; 
     
    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO); 
    GetVersionEx(&osvi); 
	 
    if(osvi.dwPlatformId == VER_PLATFORM_WIN32_NT) 
    { 
	//OS=NT/2000 
	h = CreateFile("\\\\.\\giveio", GENERIC_READ, 0, NULL, 
			OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); 
	CloseHandle(h); 
	if(h == INVALID_HANDLE_VALUE) 
    	    return 0; 
	else 
	    return 0x2000; 
    } 
    else 
    {	//OS=WIN98 
	return 0x0098; 
    } 
}