diff --git a/os/dos/exe2coff/exe2coff.c b/os/dos/exe2coff/exe2coff.c
new file mode 100644
--- /dev/null
+++ b/os/dos/exe2coff/exe2coff.c
@@ -0,0 +1,94 @@
+/* Copyright (C) 1998 DJ Delorie, see COPYING.DJ for details */
+/* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
+/* Updated 2008 to use fread/fopen and friends instead of read/open so it compiles with GCC on Unix (Rubidium) */
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <unistd.h>
+#include <ctype.h>
+
+
+static void
+exe2aout(char *fname)
+{
+  unsigned short header[3];
+  FILE *ifile;
+  FILE *ofile;
+  char buf[4096];
+  int rbytes;
+  char *dot = strrchr(fname, '.');
+  if (!dot || strlen(dot) != 4
+      || tolower(dot[1]) != 'e'
+      || tolower(dot[2]) != 'x'
+      || tolower(dot[3]) != 'e')
+  {
+    fprintf(stderr, "%s: Arguments MUST end with a .exe extension\n", fname);
+    return;
+  }
+
+  ifile = fopen(fname, "rb");
+  if (!ifile)
+  {
+    perror(fname);
+    return;
+  }
+  fread(header, sizeof(header), 1, ifile);
+  if (header[0] == 0x5a4d)
+  {
+    long header_offset = (long)header[2]*512L;
+    if (header[1])
+      header_offset += (long)header[1] - 512L;
+    fseek(ifile, header_offset, SEEK_SET);
+    header[0] = 0;
+    fread(header, sizeof(header), 1, ifile);
+    if ((header[0] != 0x010b) && (header[0] != 0x014c))
+    {
+      fprintf(stderr, "`%s' does not have a COFF/AOUT program appended to it\n", fname);
+      return;
+    }
+    fseek(ifile, header_offset, SEEK_SET);
+  }
+  else
+  {
+    fprintf(stderr, "`%s' is not an .EXE file\n", fname);
+    return;
+  }
+
+  *dot = 0;
+  ofile = fopen(fname, "w+b");
+  if (!ofile)
+  {
+    perror(fname);
+    return;
+  }
+
+  while ((rbytes=fread(buf, 1, 4096, ifile)) > 0)
+  {
+    int wb = fwrite(buf, 1, rbytes, ofile);
+    if (wb < 0)
+    {
+      perror(fname);
+      break;
+    }
+    if (wb < rbytes)
+    {
+      fprintf(stderr, "`%s': disk full\n", fname);
+      exit(1);
+    }
+  }
+  fclose(ifile);
+  fclose(ofile);
+}
+
+int
+main(int argc, char **argv)
+{
+  int i;
+  if (argc == 1) printf("Usage: %s <exename>", argv[0]);
+  for (i=1; i<argc; i++)
+    exe2aout(argv[i]);
+  return 0;
+}
+