#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#define CRLF "\r\n"

#define BASE 0xfe0000
#define RECLEN 32

void putS0(FILE* out, const char* header)
{
  int i, csum, c;
  int len = strlen(header);
  fprintf(out, "S0%02X0000", 2 + len + 1);
  csum = 0;
  for (i=0; i<len; i++) {
    c = ((int)header[i]) & 0xff;
    csum += c;
    fprintf(out, "%02X", c);
  }
  fprintf(out, "%02X" CRLF, (~csum) & 0xff);
}

void putS8(FILE* out,int start)
{
  int csum = 4 + ((BASE>>16) & 0xff) + ((BASE>>8) & 0xff) + (BASE & 0xff);
  fprintf(out, "S804%06X%02X" CRLF, BASE & 0xffffff, (~csum) &0xff);
}

void putS2(FILE* out, int addr, unsigned char* data, int n)
{
  int i, csum, c;

  fprintf(out, "S2%02X%06X", 3 + n + 1, addr & 0xffffff);
  csum = 3 + n + 1 + ((addr>>16) & 0xff) + ((addr>>8) & 0xff) + (addr & 0xff);

  for (i=0; i<n; i++) {
    c = data[i] & 0xff;
    fprintf(out, "%02X", c);
    csum += c;
  }
  fprintf(out, "%02X" CRLF, (~csum) & 0xff);
}

int main(int argc, char* argv[]) 
{
  FILE *e,*out;
  int c,i;
  unsigned char eprombuf[65536];
  int size;


  if (argc != 3) {
    fprintf(stderr,
	    "Convert a 16bit EPROM file into EXORMACS format, compatible to SIMH SAGE.\n"
	    "Usage: %s eprom.dat output.dat\n\n", argv[0]);
    exit(1);
  }

  e = fopen(argv[1], "rb");
  out =  fopen(argv[2], "wb");

  if (!e) {
    fprintf(stderr, "Could not open %s\n", argv[1]);
    exit(1);
  }
  if (!out) {
    fprintf(stderr, "Could not open %s\n", argv[2]);
    exit(1);
  }
  
  size = 0;
  do {
    if ((c = fgetc(e)) == EOF) break;
    eprombuf[size++] = c;
  } while (!feof(e));
  printf("%s: Size = %d\n", argv[2], size);
  fclose(e);

  for (i=0; i<size; i+=2) {
    c = eprombuf[i+1];
    eprombuf[i+1] = eprombuf[i];
    eprombuf[i] = c;
  }

  putS0(out, argv[2]);
  i = 0;
  for (i=0; i<size; i += RECLEN) {
    putS2(out, BASE+i, eprombuf+i, RECLEN);
  }
  putS8(out, BASE);
  fclose(out);
  exit(0);
}