diff --git a/wiringPi/test/wiringpi_test61_isr2.c b/wiringPi/test/wiringpi_test61_isr2.c
index e0d21f5..06f73ee 100644
--- a/wiringPi/test/wiringpi_test61_isr2.c
+++ b/wiringPi/test/wiringpi_test61_isr2.c
@@ -189,6 +189,14 @@ int main (void) {
 
 	wiringPiVersion(&major, &minor);
 
+  if (!piBoard40Pin()) {
+      printf("Old 28pin system\n");
+		//GPIO = 23;
+		//GPIOIN = 24;
+	  GPIO = 17;
+    GPIOIN = 18;
+  }
+
 	printf("WiringPi GPIO test program 6b (using GPIO%d (output) and GPIO%d (input))\n", GPIO, GPIOIN);
 	printf("ISR and ISR2 test (WiringPi %d.%d)\n", major, minor);
 
@@ -206,6 +214,11 @@ int main (void) {
       accuracy = 0.02;
       bounce_acc = 2.7;
       break;
+    case PI_MODEL_ZERO:
+    case PI_MODEL_ZERO_W: //ARM=1000MHz
+      accuracy = 0.02;
+      bounce_acc = 2.5;
+      break;
     default:
       accuracy = 0.012;
       bounce_acc = 1.0;