/*
  port tou kwdika c gia z80 apo ti selida
  http://www.z88dk.org/wiki/doku.php?id=libnew:examples:pi
  ston atari 8-bit ( cc65 compiler - http://cc65.github.io/cc65/ )
  ** sly*m Jan 2016 **
*/

#include <stdio.h>
#define DIGITS 1000
#define ITERNUM DIGITS / 4 * 14
typedef unsigned char byte;
unsigned long res;
unsigned int secs;

int main()
{
  long r[ITERNUM + 1];
  long i, k;
  long b, d;
  long c;
  char keyin[1];

  byte jiflow;
  byte jifmed;
  byte jifhi;

  /*
    midenismos xronou
    die8ynseis 18, 19, 20 (0x0012, 0x0013, 0x0014 RTCLOK)
  */
  *(byte*)0x0012 = 0;
  *(byte*)0x0013 = 0;
  *(byte*)0x0014 = 0;

  c = 0;

  for (i = 0; i < ITERNUM; i++)
    r[i] = 2000;

  for (k = ITERNUM; k > 0; k -= 14)
  {
    d = 0;
    i = k;

    while (1)
    {
      d += r[i] * 10000;
      b = i * 2 - 1;

      r[i] = d % b;
      d /= b;

      i--;
      if (i == 0) break;

      d *= i;
    }

    printf("%.4d", (int)(c + d / 10000));

    c = d % 10000;
  }

    jifhi = *(byte*)0x0012;
    jifmed = *(byte*)0x0013;
    jiflow = *(byte*)0x0014;

    /* vbls pou metri8ikan */
    res = (unsigned long)jifhi << 16;
    res |= (unsigned long)jifmed << 8;
    res |= (unsigned long)jiflow;

    /* dia 50 hertz (pal) = deyterolepta */
    secs = (unsigned int)(res / 50);

    printf(" ** %d sec **\npata [return]", secs);

    gets(keyin);

  return 0;
}