diff --git a/src/Prep/DemRaw2ascii/main.c b/src/Prep/DemRaw2ascii/main.c
index 2d509b4c..27829df5 100644
--- a/src/Prep/DemRaw2ascii/main.c
+++ b/src/Prep/DemRaw2ascii/main.c
@@ -1,6 +1,8 @@
 /* main.cxx -- main loop
  *
  * Written by Curtis Olson, started February 1998.
+ * Modified by Geoff McLane, March, 2009
+ * to add min, max, lon, lat, to limit the output of ASCII DEM files.
  *
  * Copyright (C) 1998, 1999  Curtis L. Olson  - http://www.flightgear.org/~curt
  *
@@ -36,29 +38,149 @@
 #  include <stdlib.h>
 #endif
 
+#include <sys/types.h>
+#include <sys/stat.h>
 #include "rawdem.h"
 
+#ifdef _MSC_VER
+#define M_ISDIR _S_IFDIR
+#else
+#define M_ISDIR __S_IFDIR
+#endif
+
+static void give_help( char * name )
+{
+   printf("Usage: %s [OPTIONS] <input_file_basename> <output_dir>\n", name);
+   printf("Options:\n");
+   printf(" --min-lat=<degs> - set minimum latitude for output.\n");
+   printf(" --max-lat=<degs> - set maximum latitude for output.\n");
+   printf(" --min-lon=<degs> - set minimum longitude for output.\n");
+   printf(" --max-lon=<degs> - set maximum longitude for output.\n");
+}
+
+static int is_file_or_directory( char * cur_item )
+{
+   struct stat buf;
+   if( stat( cur_item, &buf ) == 0 ) {
+      if ( buf.st_mode & M_ISDIR )
+         return 1; // is directory
+      else
+         return 2; // is file
+   }
+   return 0;
+}
 
 int main(int argc, char **argv) {
-    fgRAWDEM raw;
-    char basename[256], output_dir[256], hdr_file[256], dem_file[256];
+    static fgRAWDEM raw;
+    static char basename[256], output_dir[256], hdr_file[256], dem_file[256];
     int start_lat, end_lat;
     int i;
-    // double total;
-    // unsigned char buf[2];
-    // short int value;
+    int last_arg = 1;
+    double min_lat, max_lat, min_lon, max_lon;
 
-    if ( argc != 3 ) {
-	printf("Usage: %s <input_file_basename> <output_dir>\n", argv[0]);
-	exit(-1);
+#if defined( _MSC_VER ) && _MSC_VER >= 1400 // set 2-ditit exponent - defaults to 3 - Only available for VS2005
+    _set_output_format( _TWO_DIGIT_EXPONENT );
+#endif // _MSC_VER
+
+    min_lat = max_lat = min_lon = max_lon = BAD_LATLON;
+    for( i = 1; i < argc; i++ )
+    {
+       char * arg = argv[i];
+       if (*arg == '-') {
+          // option
+          if((strcmp(arg,"-h") == 0)||
+             (strcmp(arg,"--help") == 0)) {
+                give_help( argv[0] );
+                exit(0);
+          } else if( strncmp(arg,"--min-lon=", 10) == 0 ) {
+             min_lon = atof( &arg[10] );
+          } else if( strncmp(arg,"--max-lon=", 10) == 0 ) {
+             max_lon = atof( &arg[10] );
+          } else if( strncmp(arg,"--min-lat=", 10) == 0 ) {
+             min_lat = atof( &arg[10] );
+          } else if( strncmp(arg,"--max-lat=", 10) == 0 ) {
+             max_lat = atof( &arg[10] );
+          } else {
+             printf( "ERROR: Unknown argument [%s]. Use -h for help.\n", arg );
+             exit(1);
+          }
+          last_arg = i + 1;
+       } else
+          break;
     }
 
+    if ( (argc - last_arg) != 2 ) {
+       give_help( argv[0] );
+       exit(1);
+    }
+    if(( min_lat != BAD_LATLON )&&
+       (( min_lat < -90.0 )||( min_lat > 90.0 ))) {
+          printf( "ERROR: Bad min-lat [%f]!\n", min_lat );
+          exit(1);
+    }
+    if(( max_lat != BAD_LATLON )&&
+       (( max_lat < -90.0 )||( max_lat > 90.0 ))) {
+          printf( "ERROR: Bad max-lat [%f]!\n", max_lat );
+          exit(1);
+    }
+    if(( min_lon != BAD_LATLON )&&
+       (( min_lon < -180.0 )||( min_lon > 180.0 ))) {
+          printf( "ERROR: Bad min-lon [%f]!\n", min_lon );
+          exit(1);
+    }
+    if(( max_lon != BAD_LATLON )&&
+       (( max_lon < -180.0 )||( max_lon > 180.0 ))) {
+          printf( "ERROR: Bad max-lon [%f]!\n", max_lon );
+          exit(1);
+    }
+    if(( min_lat != BAD_LATLON )&&
+       ( max_lat != BAD_LATLON )&&
+       ( min_lat > max_lat ))
+    {
+       printf( "ERROR: Bad min-lat [%f] NOT less than max-lat [%f]!\n", min_lat, max_lat );
+       exit(1);
+    }
+    if(( min_lon != BAD_LATLON )&&
+       ( max_lon != BAD_LATLON )&&
+       ( min_lon > max_lon ))
+    {
+       printf( "ERROR: Bad min-lon [%f] NOT less than max-lon [%f]!\n", min_lon, max_lon );
+       exit(1);
+    }
+
+    if(( min_lat != BAD_LATLON )||
+       ( max_lat != BAD_LATLON )||
+       ( min_lon != BAD_LATLON )||
+       ( max_lon != BAD_LATLON ))
+    {
+      printf( "Limited to " );
+      if( min_lat != BAD_LATLON )
+         printf( "min lat [%f] ", min_lat );
+      if( max_lat != BAD_LATLON )
+         printf( "max lat [%f] ", max_lat );
+      if( min_lon != BAD_LATLON )
+         printf( "min lon [%f] ", min_lon );
+      if( max_lon != BAD_LATLON )
+         printf( "max lon [%f] ", max_lon );
+      printf( "\n" );
+    }
+
+    /* set any mins and max */
+    raw.min_lat = min_lat;
+    raw.min_lon = min_lon;
+    raw.max_lat = max_lat;
+    raw.max_lon = max_lon;
+
     /* get basename */
-    strcpy(basename, argv[1]);
+    strcpy(basename, argv[last_arg]);
 
     /* get output dir */
-    strcpy(output_dir, argv[2]);
-
+    strcpy(output_dir, argv[last_arg+1]);
+    if ( is_file_or_directory( output_dir ) != 1 ) {
+       printf( "ERROR: Ouput directory [%s], does not exist!\n", output_dir );
+       exit(1);
+    }
+    
     /* generate header file name */
     strcpy(hdr_file, basename);
     strcat(hdr_file, ".HDR");
diff --git a/src/Prep/DemRaw2ascii/rawdem.c b/src/Prep/DemRaw2ascii/rawdem.c
index d17f99f0..4a7da74d 100644
--- a/src/Prep/DemRaw2ascii/rawdem.c
+++ b/src/Prep/DemRaw2ascii/rawdem.c
@@ -85,7 +85,7 @@ int reads(int fd, char *buf, unsigned int len) {
  * DEM file */
 void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
     FILE *hdr;
-    char line[256], key[256], value[256];
+    static char line[256], key[256], value[256];
     int i, len, offset;
     double tmp;
 
@@ -100,7 +100,13 @@ void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
     /* process each line */
     while ( (reads(fileno(hdr), line, 256) != 0) ) {
 
-	printf("%s", line);
+   len = strlen(line);
+   while(len && ((line[len - 1] == '\n')||(line[len - 1] == '\r'))) {
+      len--;
+      line[len] = 0; // kill EOL characters
+   }
+   printf("%s ", line);
+ 
 	len = strlen(line);
 
 	/* extract key */
@@ -128,13 +134,17 @@ void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
 	if ( strcmp(key, "BYTEORDER") == 0 ) {
 	    if ( strcmp( value, "M" ) == 0 ) {
 		raw->big_endian = 1;
-	    } else {
+      printf( "- set big_endian\n" );
+      } else {
+      printf( "- unset big_endian (not 'M'!)\n" );
 		raw->big_endian = 0;
 	    }
 	} else if ( strcmp(key, "NROWS") == 0 ) {
 	    raw->nrows = atoi(value);
+       printf( "- set rows to %d\n", raw->nrows );
 	} else if ( strcmp(key, "NCOLS") == 0 ) {
 	    raw->ncols = atoi(value);
+       printf( "- set cols to %d\n", raw->ncols );
 	} else if ( strcmp(key, "ULXMAP") == 0 ) {
 	    tmp = atof(value);
 #ifdef HAVE_RINT
@@ -142,6 +152,8 @@ void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
 #else
 	    raw->ulxmap = (int)round(tmp * 3600.0); /* convert to arcsec */
 #endif
+       printf( "- set ulxmap to %d arcsecs (%d degrees)\n", raw->ulxmap,
+          raw->ulxmap / 3600);
 	} else if ( strcmp(key, "ULYMAP") == 0 ) {
 	    tmp = atof(value);
 #ifdef HAVE_RINT
@@ -149,6 +161,8 @@ void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
 #else
 	    raw->ulymap = (int)round(tmp * 3600.0); /* convert to arcsec */
 #endif
+       printf( "- set ulymap to %d arcsecs (%d degrees)\n", raw->ulymap,
+          raw->ulymap / 3600);
 	} else if ( strcmp(key, "XDIM") == 0 ) {
 	    tmp = atof(value);
 #ifdef HAVE_RINT
@@ -156,6 +170,8 @@ void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
 #else
 	    raw->xdim = (int)round(tmp * 3600.0);   /* convert to arcsec */
 #endif
+       printf( "- set xdim to %d arcsecs (%f degrees)\n", raw->xdim,
+          (double)raw->xdim / 3600.0);
 	} else if ( strcmp(key, "YDIM") == 0 ) {
 	    tmp = atof(value);
 #ifdef HAVE_RINT
@@ -163,8 +179,11 @@ void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
 #else
 	    raw->ydim = (int)round(tmp * 3600.0);   /* convert to arcsec */
 #endif
+       printf( "- set ydim to %d arcsecs (%f degrees)\n", raw->ydim,
+          (double)raw->ydim / 3600.0);
 	} else {
 	    /* ignore for now */
+      printf( "- ignore for now\n" );
 	}
     }
 
@@ -258,7 +277,7 @@ void rawReadNextRow( fgRAWDEM *raw, int index ) {
 	if ( value > raw->max ) { raw->max = value; }
     }
 
-    printf( " so far, min = %d  max = %d\n", raw->min, raw->max );
+    /* printf( " so far, min = %d  max = %d\n", raw->min, raw->max ); */
 }
 
 
@@ -331,6 +350,15 @@ void rawDumpAsciiDEM( fgRAWDEM *raw, char *path, int ilon, int ilat ) {
 
     sprintf(outfile, "%s/%c%03d%c%02d.dem", path, lon_sign, lon, lat_sign, lat);
 
+   if((( raw->min_lat != BAD_LATLON)&&( (double)ilat < raw->min_lat ))||
+      (( raw->max_lat != BAD_LATLON)&&( (double)ilat > raw->max_lat ))||
+      (( raw->min_lon != BAD_LATLON)&&( (double)ilon < raw->min_lon ))||
+      (( raw->max_lon != BAD_LATLON)&&( (double)ilon > raw->max_lon )))
+   {
+       printf("outfile = %s not written. Outside range\n", outfile);
+       return;
+   }
+
     printf("outfile = %s\n", outfile);
 
     if ( (fd = fopen(outfile, "w")) == NULL ) {
@@ -468,7 +496,7 @@ void rawProcessStrip( fgRAWDEM *raw, int lat_degrees, char *path ) {
     /* convert to arcsec */
     lat = lat_degrees * 3600;
 
-    printf("Max Latitude = %d arcsec\n", lat);
+    printf("Max Latitude = %d arcsec (%f degs)\n", lat, lat_degrees);
 
     /* validity check ... */
     if ( (lat > raw->rooty) || 
diff --git a/src/Prep/DemRaw2ascii/rawdem.h b/src/Prep/DemRaw2ascii/rawdem.h
index 8da2a70b..d615dbb1 100644
--- a/src/Prep/DemRaw2ascii/rawdem.h
+++ b/src/Prep/DemRaw2ascii/rawdem.h
@@ -30,6 +30,8 @@
 #define MAX_COLS 7200
 #define MAX_COLS_X_2 14400
 
+#define BAD_LATLON  12345.0
+
 typedef struct {
     /* header info */
     int big_endian;  /* true if data source is big, false if little */
@@ -47,7 +49,9 @@ typedef struct {
     /* file ptr */
     int fd;          /* Raw DEM file descriptor */
 
-    /* storage area for a 1 degree high strip of data.  Note, for
+    double min_lat, max_lat, min_lon, max_lon; /* some limits, if any */
+
+   /* storage area for a 1 degree high strip of data.  Note, for
      * convenience this is in y,x order */
     short strip[120][MAX_ROWS];