This is the code I talked about earlier. Just rips the bottom 2 bits out of a 4-bit bitmap to make a 2-bit bitmap. So to use this you make a 4-bit bitmap with grayscale. Black, 50% Gray, 25% Gray, White. Paint is where I made the bitmaps. It must be 128×32. The program doesn’t do any checks on this, its fairly stupid.

#include <stdio.h>

void main(void)
{
  char str[80];
  char nstr[80];
  int image[2048];
  int ripped[1024];
  int flipped[1024];
  int i,j;
  int header_junk;
  FILE *fp, *nfp;
  
  printf("4-Bit BMP File Name? : ");
  gets(str);
  printf("Opening File. : %s\n",str);
  fp = fopen(str, "r");
  if (fp == NULL) 
  {
    fprintf(stderr, "File Can Not Be Opened.\n");
    exit(1);
  }
  printf("File Opened Successful!\n");
  printf("2-Bit DMD File Name? (format XXX.DMD) : ");
  gets(nstr);
  printf("\nCreating New File Named: %s.dmd\n",str);
  nfp = fopen(nstr, "w");
  
  printf("Reading Header.\n");
  for( i = 0 ; i < 118 ; i++)
  {
    header_junk = fgetc (fp);
    printf("0x%.2X ", header_junk);
  }
  printf("\nHeader Ripped.\n");
  printf("Reading Image Data\n");
  for( i = 0 ; i < 2048 ; i ++)
  {
    image[i] = fgetc (fp);
    printf("0x%.2X ", image[i]);
  }
  printf("\nRipping bits out and Rotating!\n");
  
  for( i = 0 ; i < 1024 ; i ++)
  {
    ripped[i] = (((image[2*i] & 0x80))| ((image[2*i] & 0x40)) | ((image[2*i] & 0x08)<<2) | ((image[2*i] & 0x04)<<2) | ((image[2*i+1] & 0x80) >> 4) | ((image[2*i+1] & 0x40) >> 4) | ((image[2*i+1] & 0x08) >>2) | ((image[2*i+1] & 0x04) >>2));
    printf("0x%.2X ", ripped[i]);
  }
  
  printf("\nFlipping Image.\n");

  for( j = 0 ; j < 32 ; j ++)
  {  
    for( i = 0 ; i < 32 ; i++)
    {
      flipped [(992-(32*j))+i] =  ripped[(32*j)+i]; 
    }
  }  
  
  printf("\nWriting To New File\n");
  
  for( i = 0 ; i < 1024 ; i++)
  {
    fputc(flipped[i],nfp);
    printf("0x%.2X ", flipped[i]);
  }
  fclose(nfp);
  fclose(fp);
  
  printf("\nDone!\n");
  printf("Press Any Key To Quit...");
  gets(str);
  exit(1);
}