diff --git a/cntr/fw/cntr/cntr.c b/cntr/fw/cntr/cntr.c
index 9bd8ead..9f0bf54 100644
--- a/cntr/fw/cntr/cntr.c
+++ b/cntr/fw/cntr/cntr.c
@@ -18,20 +18,37 @@
 #include "usb.h"
 #include "cntr/ep0.h"
 #include "version.h"
+#include "cntr.h"
 
 
-/*
- * Free-running 32 bit counter. The lower two bytes are from hardware Timer 0.
- * The upper two bytes are maintained by software. At the maximum input clock
- * frequency of 6 MHz, it wraps around every 11.9 minutes, leaving the host
- * plenty of time to read it.
- */
-
 uint8_t cntr[4];
+enum hw_type hw_type = HW_TYPE_V1;
+
+
+static void delay(unsigned ms)
+{
+        int x;
+
+	while (ms--)
+	        for (x = 0; x < 1488; x)
+	       	         x++;
+}
 
 
 static void init_io(void)
 {
+	if (VERSION_ID) {
+		/* flash LED a second time */
+		LEDv2 = 0;
+		delay(250);
+		LEDv2 = 1;
+		delay(250);
+
+		PROBE_TERM_MODE |= 1 << PROBE_TERM_BIT;
+
+		hw_type = HW_TYPE_V2;
+	}
+
 	/*
 	 * Signal	Mode		Value
 	 *
@@ -39,9 +56,11 @@ static void init_io(void)
 	 * PROBE_ECI	open drain	1	(input)
 	 * PROBE_INT0	open drain	1	(input)
 	 *
-	 * PROBE_TERM	open drain	0
+	 * PROBE_TERM	open drain	0	version 1
+	 * PROBE_TERM	push-pull	1	version 2
 	 *
-	 * LED		push-pull	0	(set up by boot loader)
+	 * LEDv1	push-pull	0	(set up by boot loader)
+	 * LEDv2	push-pull	0	(set up by boot loader)
 	 *
 	 * all unused	open drain 	0
 	 */
@@ -51,6 +70,9 @@ static void init_io(void)
 	P2 = 0;
 	P3 = 0;
 
+	if (hw_type == HW_TYPE_V2)
+		PROBE_TERM = 1;
+
 	/*
 	 * Disable pull-ups
 	 */
diff --git a/cntr/fw/cntr/cntr.h b/cntr/fw/cntr/cntr.h
new file mode 100644
index 0000000..db248c8
--- /dev/null
+++ b/cntr/fw/cntr/cntr.h
@@ -0,0 +1,30 @@
+/*
+ * cntr/cntr.h - CNTR global variables
+ *
+ * Written 2010 by Werner Almesberger
+ * Copyright 2010 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef CNTR_H
+#define CNTR_H
+
+/*
+ * Free-running 32 bit counter. The lower two bytes are from hardware Timer 0.
+ * The upper two bytes are maintained by software. At the maximum input clock
+ * frequency of 6 MHz, it wraps around every 11.9 minutes, leaving the host
+ * plenty of time to read it.
+ */
+
+extern uint8_t cntr[4];
+
+extern enum hw_type {
+	HW_TYPE_V1 = 0,
+	HW_TYPE_V2 = 1,
+} hw_type;
+
+#endif /* !CNTR_H */
diff --git a/cntr/fw/cntr/ep0.c b/cntr/fw/cntr/ep0.c
index fedb589..78277ee 100644
--- a/cntr/fw/cntr/ep0.c
+++ b/cntr/fw/cntr/ep0.c
@@ -21,6 +21,7 @@
 #include "usb.h"
 #include "cntr/ep0.h"
 #include "version.h"
+#include "cntr.h"
 
 #define debug(...)
 #define error(...)
@@ -51,9 +52,11 @@
     } while (0)
 
 
-extern uint8_t cntr[8];
+static uint8_t id[3] = {
+	EP0CNTR_MAJOR, EP0CNTR_MINOR,
+	/* hw type is set at run time */
+};
 
-static const uint8_t id[] = { EP0CNTR_MAJOR, EP0CNTR_MINOR, HW_TYPE };
 static __xdata uint8_t buf[128];
 
 
@@ -74,6 +77,7 @@ static __bit my_setup(struct setup_request *setup) __reentrant
 		debug("CNTR_ID\n");
 		if (setup->wLength > 3)
 			return 0;
+		id[2] = hw_type;
 		usb_send(&ep0, id, setup->wLength, NULL, NULL);
 		return 1;
 	case CNTR_FROM_DEV(CNTR_BUILD):
diff --git a/cntr/fw/common/config.h b/cntr/fw/common/config.h
index fe97eaf..7a7afd4 100644
--- a/cntr/fw/common/config.h
+++ b/cntr/fw/common/config.h
@@ -48,9 +48,4 @@
 	LEDv1 = 0;	\
 	LEDv2 = 0
 
-
-/* ----- Application configuration ----------------------------------------- */
-
-#define	HW_TYPE		0
-
 #endif /* !CONFIG_H */
diff --git a/cntr/fw/common/io.h b/cntr/fw/common/io.h
index b80448e..6b798dd 100644
--- a/cntr/fw/common/io.h
+++ b/cntr/fw/common/io.h
@@ -34,4 +34,14 @@
 
 #define	PROBE_TERM	P1_2
 
+/*
+ * Version ID
+ *
+ * In version 1, P2_1 is used to provide ground to the input side. In version
+ * 2, we use a ground place for this and P2_1 is unconnected. We can therefore
+ * use it to identify the hardware version.
+ */
+
+#define	VERSION_ID	P2_1
+
 #endif /* !IO_H */