diff --git a/ubb-vga/ubb-vga.c b/ubb-vga/ubb-vga.c
index 0a5b7e2..e0f20e3 100644
--- a/ubb-vga/ubb-vga.c
+++ b/ubb-vga/ubb-vga.c
@@ -415,15 +415,36 @@ static void session(void (*gen)(void **fb, int xres, int yres), int frames)
 }
 
 
+static void list_modes(void)
+{
+	const struct mode *m;
+
+	for (m = mode_db; m->name; m++) {
+		printf("\"%s\", %dx%d:\n", m->name, m->xres, m->yres);
+		printf("\t336/%d = %5.2f MHz\n",
+		    m->clkdiv+1, 336.0/(m->clkdiv+1));
+		printf("\tH: %4.2f+...+%4.2f = %5.2f us\n",
+		    CYCLES(m->hsync_cycles), CYCLES(m->hback_cycles),
+		    CYCLES(m->line_cycles));
+		printf("\tV: %d+%d+%d+%d lines, %5.2f Hz\n",
+		    m->vsync_lines, m->vfront_lines, m->yres, m->vback_lines,
+		    112000000.0/m->line_cycles/
+		    (m->vsync_lines+m->vfront_lines+m->yres+m->vback_lines));
+	}
+}
+
+
 static void usage(const char *name)
 {
 	fprintf(stderr,
-"usage: %s [-t] [-r resolution] frames [file]\n\n"
+"usage: %s [-t] [-r resolution] [frames [file]]\n"
+"       %s -l\n\n"
 "  frames  number of frames to display\n"
 "  file    PPM file\n\n"
+"  -l       list available modes\n"
 "  -m mode  select the display mode, default \"%s\"\n"
 "  -t       generate a test image\n"
-    , name, mode_db[0].name);
+    , name, name, mode_db[0].name);
 	exit(1);
 }
 
@@ -434,8 +455,11 @@ int main(int argc, char *const *argv)
 	int frames = 0;
 	int c;
 
-	while ((c = getopt(argc, argv, "m:t")) != EOF)
+	while ((c = getopt(argc, argv, "lm:t")) != EOF)
 		switch (c) {
+		case 'l':
+			list_modes();
+			exit(0);
 		case 'm':
 			for (mode = mode_db; mode->name; mode++)
 				if (!strcmp(mode->name, optarg))
@@ -466,12 +490,6 @@ int main(int argc, char *const *argv)
 		usage(*argv);
 	}
 
-#if 0
-printf("V: %d+%d+%d+%d\n", mode->vsync_lines, mode->vfront_lines,
-  mode->yres, mode->vback_lines);
-printf("H: %4.1f+?+?+%4.1f (%4.1f)\n", CYCLES(mode->hsync_cycles),
-  CYCLES(mode->hback_cycles), CYCLES(mode->line_cycles));
-#endif
 	setup();
 	session(gen, frames);
 	cleanup();