diff --git a/demo/Makefile b/demo/Makefile
index d02789c..e93cca9 100644
--- a/demo/Makefile
+++ b/demo/Makefile
@@ -6,7 +6,7 @@ LDFLAGS = -L../lib/ -lcomedi -lm
 
 
 BINS=cmd tut1 tut2
-MBINS=inp inpn sv eeprom_dump info outp insn antialias ao_waveform
+MBINS=inp inpn sv eeprom_dump info outp insn antialias ao_waveform dio
 
 all: $(patsubst %,_mbins_%,$(MBINS)) $(patsubst %,_bins_%,$(BINS))
 
diff --git a/demo/dio.c b/demo/dio.c
new file mode 100644
index 0000000..2b3bdbc
--- /dev/null
+++ b/demo/dio.c
@@ -0,0 +1,75 @@
+/*
+ * Digital I/O example
+ * Part of Comedilib
+ *
+ * Copyright (c) 1999,2000 David A. Schleef <ds@schleef.org>
+ *
+ * This file may be freely modified, distributed, and combined with
+ * other software, as long as proper attribution is given in the
+ * source code.
+ */
+/*
+ * Requirements:  A board with a digital I/O subdevice.  Not just
+ *    a 'digital input' or 'digital output' subdevice, but one in
+ *    which the channels can be configured between input and output.
+ */
+
+#include <stdio.h>
+#include <comedilib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <getopt.h>
+#include <ctype.h>
+#include "examples.h"
+
+comedi_t *device;
+
+
+int main(int argc, char *argv[])
+{
+	int ret;
+	int stype;
+	int i;
+	unsigned int mask;
+	unsigned int data;
+
+	parse_options(argc,argv);
+
+	device=comedi_open(filename);
+	if(!device){
+		comedi_perror(filename);
+		exit(0);
+	}
+
+	stype = comedi_get_subdevice_type(device,subdevice);
+	if(stype!=COMEDI_SUBD_DIO){
+		printf("%d is not a digital I/O subdevice\n",subdevice);
+		exit(0);
+	}
+
+	printf("configuring pin %d for output...\n",channel);
+
+	ret=comedi_dio_config(device,subdevice,channel,COMEDI_OUTPUT);
+	
+	printf("toggling pin %d rapidly...\n",channel);
+
+	for(i=0;i<10000;i++){
+		comedi_dio_write(device,subdevice,channel,1);
+		comedi_dio_write(device,subdevice,channel,0);
+	}
+
+	printf("toggling pin %d rapidly (using bitfield)...\n",channel);
+
+	mask = 1<<channel;
+	for(i=0;i<10000;i++){
+		data = mask;
+		comedi_dio_bitfield(device,subdevice,mask,&data);
+		data = 0;
+		comedi_dio_bitfield(device,subdevice,mask,&data);
+	}
+
+	return 0;
+}
+