LLSTUFF.BAK

/*
 *
 * Low level stuff
 *
 * by Micro-Ed
 *
 */

#include "Micro-Ed.H"
#pragma inline




extern unsigned _stklen = 1024 * 12 ;




static int      	  HandleCE (int nErrCode, int AX, int BP, int SI) ;
static void interrupt NewClockHandler (void) ;
static int      	  CtrlBrkHandler (void) ;
static void 		  TestDosVersion (void) ;
static void 		  GetWindowsStatus (void) ;
static void interrupt NewCEHandler (unsigned BP, unsigned DI, unsigned SI,
									unsigned DS, unsigned ES, unsigned DX,
									unsigned CX, unsigned BX, unsigned AX) ;




void InitLowLevStuff (void)
{
	bDodgy = FALSE ;
	setvect (0x1c, NewClockHandler) ;
	asm {
		mov ah, 12h
		mov al, 01h
		mov bl, 32h
		int 10h
	} ;
	bDodgy = TRUE ;
	asm int 03h
	bDodgy = FALSE ;
	asm {
		mov ah, 12h
		mov al, 00h
		mov bl, 32h
		int 10h
	} ;
	setvect (0x1c, lpOldClockHandler) ;

	asm {
		int	01h
		int 03h
		lea	bx, lblPatch
		mov	cs:[bx + 2], 019cdh
lblPatch:
	} ;

	TestDosVersion () ;

	ctrlbrk (CtrlBrkHandler) ;

	lpOldCEHandler = getvect (0x24) ;
	setvect (0x24, NewCEHandler) ;

	GetWindowsStatus () ;

	ScrInit	() ;
}

void interrupt NewClockHandler (void)
{
	if (bDodgy == TRUE)
	{
		asm cli
Loop:
		asm jmp Loop
	}

	lpOldClockHandler () ;
}

void RestLowLevStuff (void)
{
	setvect (0x24, lpOldCEHandler) ;
}

#pragma argsused
void interrupt NewCEHandler (unsigned BP, unsigned DI, unsigned SI,
							 unsigned DS, unsigned ES, unsigned DX,
							 unsigned CX, unsigned BX, unsigned AX)
{
	enable () ;
	AX = HandleCE (DI & 0x00ff, AX, BP, SI) ;
	return ;
}

static int HandleCE (int nErrCode, int AX, int BP, int SI)
{
	int			  nLongestStrLen ;
	char		  szErrMessage1 [80], szErrMessage2 [80], szDevice [9], szDrive [20] ;
	char          szPrompt [] = "Press R to retry operation or ESC to cancel" ;
	char   far  * lpDevAttr ;
	static char * szErrors [] =
	{
		"Write-protected disk ",
		"Unknown unit ",
		"Not ready ",
		"Unknown command " ,
		"Data error (CRC) ",
		"Bad request-structure length ",
		"Seek error ",
		"Unknown media type ",
		"Sector not found ",
		"Printer out of paper ",
		"Write fault ",
		"Read fault ",
		"General failure "
	} ;

	ceScrPush () ;
	DrawMenuBar (NO_DROP_DOWNS, FALSE, FALSE) ;
	DrawStatusBar (0) ;

	strcpy (szErrMessage1, szErrors [nErrCode]) ;

	if (AX & 0x8000) // Character device error or bad FAT:
	{
		lpDevAttr = MK_FP (BP, SI + 5) ;
		if (* lpDevAttr & 0x80) // Character device error.
		{
			movedata (BP, SI + 10,
					  FP_SEG ((char far *)szDevice),
					  FP_OFF ((char far *)szDevice), 8) ;
			szDevice [8] = '\x0' ;
			sprintf (szErrMessage2, "error accessing device %s", szDevice) ;
		}
		else
			strcpy (szErrMessage2, "(bad memory image of FAT)") ;
	}
	else // Disk error:
	{
		sprintf (szDrive, "drive %c", 'A' + AX & 0x00ff) ;
		if (nErrCode != 2)
		{
			if (AX & 0x0100)
				strcpy (szErrMessage2, "error writing ") ;
			else
				strcpy (szErrMessage2, "error reading ") ;
			strcat (szErrMessage2, szDrive) ;
		}
		else
		{
			strcpy (szErrMessage1, "No disk in ") ;
			strcpy (szErrMessage2, szDrive) ;
			strcat (szErrMessage2, "!") ;
		}
	}

	strcat (szErrMessage1, szErrMessage2) ;
	nLongestStrLen = strlen (szErrMessage1) > strlen (szPrompt)
						? strlen (szErrMessage1)
						: strlen (szPrompt) ;
	DrawBox ("Error", 9, 40 - (nLongestStrLen / 2) - 3,
					 12, 40 + (nLongestStrLen / 2) + 3) ;
	CText (szErrMessage1, nColours [C_ID_NORM],    5, 75, 10) ;
	CText (szPrompt,      nColours [C_ID_HILIGHT], 5, 75, 11) ;
	for (;;)
		switch (tolower (KbdGetC () & 0x00ff))
		{
			case 'r':
				ceScrPop () ;
				return (1) ;

			case ESC_KEY:
				ceScrPop () ;
				return (3) ;
		}
}

int CtrlBrkHandler (void)
{
	return (TRUE) ;	// Ignore Ctrl+C
}

void TestDosVersion (void)
{
	int nMinMaj = 3, nMinMin = 3 ;

	if (_osmajor > nMinMaj)
		return ;

	if (_osmajor == nMinMaj)
		if (_osminor >= nMinMin)
			return ;

	printf ("This program requires MS-DOS %d.%d or greater.\n", nMinMaj, nMinMin) ;
	exit (1) ;
}

void GetWindowsStatus (void)
{
	_AX = 0x1600 ;
	geninterrupt (0x2f) ;

	if (_AL == 0x80 || _AL == 0x00)
		bWindowsRunning = FALSE ;
	else
		bWindowsRunning = TRUE ;
}