--- a/tools/64vw.c	Mon May 27 05:59:57 2019 +0300
+++ b/tools/64vw.c	Mon May 27 06:01:32 2019 +0300
@@ -23,6 +23,9 @@
         optListOnly  = FALSE;
 size_t  noptFilenames1 = 0, noptFilenames2 = 0;
 char    **optFilenames = NULL;
+char    *optCharROMFilename = NULL;
+
+DMC64MemBlock setCharROM;
 
 
 static const DMOptArg optList[] =
@@ -36,6 +39,7 @@
     { 6, 'i', "info",       "Print information only (no display)", OPT_NONE },
     { 7, 'l', "list",       "Output list of files that were recognized (implies -i)", OPT_NONE },
     { 8, 'p', "probe",      "Probe only (do not attempt to decode the image)", OPT_NONE },
+    { 9, 'G', "char-rom",   "Set character ROM file to be used.", OPT_ARGREQ },
 };
 
 const int optListN = sizeof(optList) / sizeof(optList[0]);
@@ -155,6 +159,10 @@
             optProbeOnly = TRUE;
             break;
 
+        case 9:
+            optCharROMFilename = optArg;
+            break;
+
         default:
             dmErrorMsg("Unknown option '%s'.\n", currArg);
             return FALSE;
@@ -208,7 +216,7 @@
 }
 
 
-int dmDecodeC64Image(const DMC64Image *cimage, const DMC64ImageFormat *fmt,
+int dmDecodeC64Image(DMC64Image *cimage, const DMC64ImageFormat *fmt,
     SDL_Surface *surf, const DMC64ImageConvSpec *spec)
 {
     DMImage bmap;
@@ -224,11 +232,17 @@
     if ((ret = dmSetDefaultC64Palette(&bmap)) != DMERR_OK)
         return ret;
 
+    if (cimage->charData->data == NULL)
+        cimage->charData = &setCharROM;
+
     if (fmt->format->convertFrom != NULL)
         ret = fmt->format->convertFrom(&bmap, cimage, fmt, spec);
     else
         ret = dmC64ConvertGenericBMP2Image(&bmap, cimage, fmt, spec);
 
+    if (cimage->charData == &setCharROM)
+        cimage->charData = NULL;
+
     SDL_SetPaletteColors(surf->format->palette, (SDL_Color *) bmap.pal->colors, 0, bmap.pal->ncolors);
 
     dmPaletteFree(bmap.pal);
@@ -252,6 +266,7 @@
     dmC64InitializeFormats();
     dmSetScaleFactor(2.0);
     memset(&spec, 0, sizeof(spec));
+    memset(&setCharROM, 0, sizeof(setCharROM));
 
     dmInitProg("64vw", "Display some C64 bitmap graphics formats", "0.4", NULL, NULL);
 
@@ -321,6 +336,20 @@
         goto exit;
     }
 
+    // Check character ROM filename
+    if (optCharROMFilename == NULL)
+        optCharROMFilename = DM_DEF_CHARGEN;
+
+    // Attempt to read character ROM
+    dmMsg(1, "Using character ROM file '%s'.\n",
+        optCharROMFilename);
+
+    if ((ret = dmReadDataFile(NULL, optCharROMFilename, &setCharROM.data, &setCharROM.size)) != DMERR_OK)
+    {
+        dmErrorMsg("Could not read character ROM from '%s'.\n",
+            optCharROMFilename);
+    }
+
     // Initialize libSDL
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) != 0)
     {
@@ -546,6 +575,7 @@
 exit:
     // Cleanup
     dmFree(optFilenames);
+    dmC64MemBlockFree(&setCharROM);
 
     if (texture != NULL)
         SDL_DestroyTexture(texture);