diff --git a/ubb-la/ubb-la.c b/ubb-la/ubb-la.c
index ebeb3f7..286a787 100644
--- a/ubb-la/ubb-la.c
+++ b/ubb-la/ubb-la.c
@@ -24,6 +24,8 @@
 #include <ubb/mmcclk.h>
 #include <ubb/physmem.h>
 
+#include "gui.h"
+
 
 #define	DMA	5
 
@@ -266,7 +268,7 @@ static void print_samples(FILE *file, uint8_t *buf, int skip, int nibbles)
 /* ----- Capture ----------------------------------------------------------- */
 
 
-static int do_buf(int nibbles, uint32_t trigger, uint32_t mask)
+static int do_buf(int nibbles, uint32_t trigger, uint32_t mask, int use_gui)
 {
 	uint8_t *buf = physmem_malloc(4096);
 	struct physmem_vec vec;
@@ -288,7 +290,10 @@ static int do_buf(int nibbles, uint32_t trigger, uint32_t mask)
 	if (!xfer(vec.addr, nibbles, trigger, mask))
 		return 0;
 
-	print_samples(stdout, buf, INITIAL_SKIP, nibbles);
+	if (use_gui)
+		gui(buf, INITIAL_SKIP, nibbles);
+	else
+		print_samples(stdout, buf, INITIAL_SKIP, nibbles);
 
 	return 1;
 }
@@ -367,10 +372,12 @@ static unsigned long xlat_pins(unsigned long pins)
 static void usage(const char *name)
 {
 	fprintf(stderr,
-"usage: %s [-C] [-t pattern/mask] [(-f|-F) frequency_MHz] [-n N]\n\n"
+"usage: %s [-C] [-t pattern/mask] [(-f|-F) frequency_MHz] [-g] [-n N]\n\n"
 "  -C               output the MMC clock on CLK/TRIG (for debugging)\n"
 "  -f freq_MHz      select the specified frequency (default; 1 MHz)\n"
 "  -F freq_MHz      like -f, but also allow \"overclocking\"\n"
+"  -g               display the captured waveforms graphically (default:\n"
+"                   print as text to standard output)\n"
 "  -n N             capture N buffers worth of samples without waiting for a\n"
 "                   trigger\n"
 "  -t pattern/mask  start capture at the specified pattern (DAT0 = 1, etc.,\n"
@@ -387,11 +394,12 @@ int main(int argc, char **argv)
 	unsigned long trigger = 1, mask = 0;
 	unsigned long multi = 0;
 	int clkout = 0;
+	int use_gui = 0;
 	struct mmcclk clk, fast_clk;
 	char *end;
 	int c, res;
 
-	while ((c = getopt(argc, argv, "Cf:F:n:t:")) != EOF)
+	while ((c = getopt(argc, argv, "Cf:F:gn:t:")) != EOF)
 		switch (c) {
 		case 'C':
 			clkout = 1;
@@ -404,6 +412,9 @@ int main(int argc, char **argv)
 			if (*end)
 				usage(*argv);
 			break;
+		case 'g':
+			use_gui = 1;
+			break;
 		case 'n':
 			multi = strtoul(optarg, &end, 0);
 			if (*end)
@@ -444,8 +455,11 @@ int main(int argc, char **argv)
 		mask = UBB_CLK;
 	}
 
+	if (use_gui)
+		gui_init();
+
 	if (!multi) {
-		res = !do_buf(8128, trigger, mask);
+		res = !do_buf(8128, trigger, mask, use_gui);
 	} else {
 		frequency(&fast_clk, 84e6, 1);
 		do_bufs(multi, 8128, &clk, &fast_clk);