#include <stdio.h>
#include <dos.h>
#include <conio.h>
#include <math.h>
#include <process.h>

#define VGA256          0x13
#define TEXT_MODE       0x03

unsigned char far * video_buffer;
unsigned long int n = 1000000;
double xr_inc = 4.0/320.0;
double xi_inc = 40.0/320.0;
double xr_init = 0;
double xi_init = 936390;
double xr, xi, valuer, valuei;
long int i,j;
float k;
unsigned char c;

void Print_Scr(void){
FILE *in_fp, *out_fp;
long int i,j;
unsigned char c;
in_fp = fopen("template.pcx", "rb");
out_fp = fopen("temp.pcx","wb");
for(i=0;i<128;i++){
fread(&c, sizeof(char), 1, in_fp);
fwrite(&c, sizeof(char), 1, out_fp);
}

for(i=0;i<64000;i++){
c = video_buffer[i];
if(c<192){
fwrite(&c, sizeof(char), 1, out_fp);}
else{
c=193;
fwrite(&c, sizeof(char), 1, out_fp);
c = video_buffer[i];
fwrite(&c, sizeof(char), 1, out_fp);
}
}

fclose(in_fp);
fclose(out_fp);
printf("PrintScr successful");

}				//End function Print_Scr

double Zeta_Real(double real, double imag){
long int count;
double logc,logn;
double a,b,c,d;
double first, second;
double sum, integral, trap;

sum=0;
logn = log(n);
for(count=1;count<n;count++){
logc = log(count);
first = exp(-real*logc);
second = cos(-imag*logc);
sum+=first*second;
}
a=real-1;
b=imag;
c=cos(-imag*logn);
d=sin(-imag*logn);
integral=exp(-a*logn)*(a*c+b*d)/(a*a+b*b);

trap=exp(-real*logn)*cos(-imag*logn)/2.0;

return(sum+integral+trap);
}

void Set_Video_Mode(int mode){
union REGS inregs,outregs;
inregs.h.ah = 0;
inregs.h.al = (unsigned char)mode;
int86(0x10, &inregs, &outregs);}

void main(void)
{
	video_buffer = (unsigned char far *) 0xA0000000L;
	Set_Video_Mode(VGA256);
	double sumr, sumi,logc;
	double first, secondr, secondi;
	long int count;
	double real = .5;
	double imag = 936391;
	float f = 200.0;

	sumr=0;
	sumi=0;

	for(count=1;count<n;count++){
	logc = log(count);
	first = exp(-real*logc);
	secondr = cos(-imag*logc);
	secondi = sin(-imag*logc);
	sumr+=first*secondr;
	sumi+=first*secondi;

	if(sumr*f<160&&sumr*f>-160&&sumi*f<100&&sumi*f>-100)
	video_buffer[sumr*f+320*(int)(sumi*f)+32160]=1;

	if(kbhit()){
	Print_Scr();
	return;
	}

	}

	Print_Scr();


	while(!kbhit()){}
	Set_Video_Mode(TEXT_MODE);
}