Category : Files from Magazines
Archive   : VOL7N22.ZIP
Filename : QWRITE.C

/* qwrite.c
*/


int qwrite(int row, int col, char attrib, char *string)
{
extern int far *scrptr;
int far *farptr;
register int j;

row *= 80; /* reset row for offset into video buffer */

row += col; /* add column offset to get to first byte */

if(!string[0]) /* if no bytes to be written, return */
return row;

farptr = scrptr + row;
if( scrptr == (int far *)0xb8000000)
WaitForRetrace();

/* put attribute into DH and while not end of string */
for( j = 0, _DH = attrib; string[j]; j++)
{
_DL = string[j]; /* put character into DL */
farptr[j] = _DX; /* poke them into the buffer */
}
return row;
}

#ifdef OLD
WaitForRetrace()
{
_DX = 0x3da; /* get address of video port */
while(( inportb(_DX) & 8) != 8); /* wait if retrace in progress */
while(( inportb(_DX) & 8) == 8); /* wait for next retrace */
}
#endif
WaitForRetrace()
{
_DX = 0x3da; /* get address of video port */
while(!( inportb(_DX) & 8)); /* wait if retrace in progress */
while(( inportb(_DX) & 8)); /* wait for next retrace */
}
int far *scrptr;
Init_scrptr()
{
if( peekb(0x40, 0x49) == 0x7) /* test for mono */
scrptr = (int far *)0xb0000000;/* set pointer to mono screen buffer */
else
scrptr = (int far *)0xb8000000;/* set pointer to color screen buffer */
}

main()
{
int i,j;

Init_scrptr();

for( i = j = 0; i < 24; i++, j++)
qwrite(i,j,0x7, "This is normal video ");
getch();
for( i = j = 0; i < 24; i++, j++)
qwrite(i,j,0x70,"This is reverse video");
getch();
for( i = j = 0; i < 24; i++, j++)
qwrite(i,j,0x7, "This is normal video ");

}