diff --git a/GPIO/ATtiny412/ring.t412.ino b/GPIO/ATtiny412/ring.t412.ino
index 8d0321260ef90b085e7a15850f77c86bff047c38..82486f40118ee688108170fad05e8fe929da6c35 100644
--- a/GPIO/ATtiny412/ring.t412.ino
+++ b/GPIO/ATtiny412/ring.t412.ino
@@ -21,7 +21,7 @@ void setup() {
 void loop() {
    while(1) {
       //
-      // VPORT: 1.818 MHz
+      // VPORT: 1.808 MHz
       //    250 ns high (5 cycles), 300 ns low (6 cycles)
       //
       if (VPORTA.IN & PIN7_bm)
@@ -38,7 +38,7 @@ void loop() {
          PORTA.OUTSET = PIN6_bm;
       */
       //
-      // library: 0.358 MHz
+      // digitalRead/Write: 0.331 MHz
       //
       /*
       if (digitalRead(1))
@@ -46,5 +46,14 @@ void loop() {
       else
          digitalWrite(0,HIGH);
       */
+      //
+      // digitalReadFast/WriteFast: 1.808 MHz
+      //
+      /*
+      if (digitalReadFast(1))
+         digitalWriteFast(0,LOW);
+      else
+         digitalWriteFast(0,HIGH);
+      */
       }
    }
diff --git a/index.html b/index.html
index f8524ed5b57319d81b4db1053563877ba2a12c42..d740dcc68c38f08466623ffbdd45f972fb05f3f9 100644
--- a/index.html
+++ b/index.html
@@ -103,7 +103,14 @@ The GPIO test measures how quickly pins can communicate with a processor core; t
 </tr>
 
 <tr>
-<td>1.818</td>
+<td>1.808</td>
+<td>ATtiny412</td>
+<td><a href=GPIO/ATtiny412/ring.t412.ino>DigitalReadFast/WriteFast</a></td>
+<td>March, 2021</td>
+</tr>
+
+<tr>
+<td>1.808</td>
 <td>ATtiny412</td>
 <td><a href=GPIO/ATtiny412/ring.t412.ino>VPORT</a></td>
 <td>November, 2020</td>