Category : Files from Magazines
Archive   : ISSUE-34.ZIP
Filename : C34.FIG

(( This is C'ing Figure 1 -- Check For Hercules Card ))

#define STATUS 0x3ba

herc() /** courtesy of Hercules Corp. */
{
char test;
unsigned i;

test = inb(STATUS) & 0x80;
for(i=0;i<0x8000;i++) if( (inb(STATUS) & 0x80) != test ) return 1;
/* it's graphics!! */
return 0; /* no retrace bit change, no herc card */
}

**********************************************

(( This is C'ing Figure 2 -- Getting A Hercules Card In & Out Of
Graphics Mode ))


#define INDEX 0x3b4 /* index register for herc adapter */
#define MODE 0x3b8 /* mode control adapter */
#define CONFIG 0x3bf /* configuration switch */
#define TEXT 0x29 /* text setting for mode control */
/* This could be 0x28, but 0x29 keeps mono card from self-destructing
if you accidentally call the wrong video card */
h_tograph()
{
outb(3,CONFIG); /* set to full screen buffer=both pages activated */
outb(CON | 2,MODE); /* set to graphics mode */
crtout(0,0x35);
crtout(1,0x2d);
crtout(2,0x2e);
crtout(3,0x7);
crtout(4,0x5b);
crtout(5,0x2);
crtout(6,0x57);
crtout(7,0x57);
crtout(8,0x2);
crtout(9,0x3);
crtout(10,0x0);
crtout(11,0x0);
crtout(12,0x0);
crtout(13,0x0);
crtout(14,0x0);
crtout(15,0x0);
crtout(16,0x0);
crtout(17,0x0);
}
/************/
h_fromgraph()
{
outb(CON,MODE); /* text mode */
outb(0,CONFIG); /* cancel paging */
crtout(0,0x61);
crtout(1,0x50);
crtout(2,0x52);
crtout(3,0xf);
crtout(4,0x19);
crtout(5,0x6);
crtout(6,0x19);
crtout(7,0x19);
crtout(8,0x2);
crtout(9,0xd);
crtout(10,0xb);
crtout(11,0xc);
crtout(12,0x0);
crtout(13,0x0);
crtout(14,0x0);
crtout(15,0x0);
crtout(16,0x0);
crtout(17,0x0);
}
/***************/
crtout(reg,val)
char reg,val;
{
outw(reg+0x100*val,INDEX);

****************************************************************************


(( This is C'ing Figure 3 -- Draw Your Own Sine Wave ))


#include /* for interrupt calling */
#define pi 3.1416
unsigned scrseg;
double x_ratio,y_ratio;
struct regs rr;
char *cptr;

main()
{
unsigned i,j,*intptr,x_count,y_count,mid_x,mid_y,scrsize;
char *hold;

interrupt(0x11,&rr); /* use int 11h to find text mode */
scrseg = ( (rr.ax >> 4) & 3 == 3) ? 0xb000 : 0xb800;
if( (scrseg == 0xb000) && !herc() ) exit(); /* exit if no graphics */
if(scrseg==0xb000){
x_count=720;
y_count=348;
scrsize=0x8000;
}
else{
x_count=640;
y_count=200;
scrsize=0x4000;
}
mid_x = x_count/2; /* mid screen */
mid_y = y_count/2;
y_ratio= 2.6667/y_count;
x_ratio = 2*pi/x_count; /* one cycle of sine */
hold=malloc(0x8000); /* allocate and clear buffer */
memset(hold,0,0x8000);
for(i=0,cptr=hold;i pixel(i,mid_y-sineconv(i-mid_x)); /* origin at mid screeen */
pixel(i,mid_y); /* draw in y-axis */
}
for(i=0;i if(scrseg==0xb000) h_tograph(); else c_tograph(); /* to graph mode*/
poke(scrseg,0,hold,scrsize); /* send buffer to screen memory */
getchar();
if(scrseg==0xb000) h_fromgraph(); else c_fromgraph();
clr('s'); /* clear screen routine */
}
/*****************/
sineconv(x)
int x;
{
double sin();

return (int) (sin((x)*x_ratio)/y_ratio);
} /* using a cast to truncate floating point */
/*****************/
pixel(x,y)
int x,y;
{
unsigned offset;

offset=(scrseg==0xb000) ? 0x2000*(y&3) + 90*(y>>2) + (x>>3)
: 0x2000*(y&1) + 80*(y>>1) + (x>>3);
cptr[offset] |= 0x80 >> (x&7); /* cptr points to base of buffer */
} /* or-ing pixel position with the graphics screen byte */
/****************/
c_tograph()
{
rr.ax=6; /* go to high resolution mode*/
interrupt(0x10,&rr);
}
/********************/
c_fromgraph()
{
rr.ax=3; /* back to text mode */
interrupt(0x10,&rr);
}
/********************/
....AND INCLUDE THE CODE FROM THE OTHER FIGURES