diff --git a/tmk_core/protocol/ibmpc.cpp b/tmk_core/protocol/ibmpc.cpp
index 1d34b233..df09cb98 100644
--- a/tmk_core/protocol/ibmpc.cpp
+++ b/tmk_core/protocol/ibmpc.cpp
@@ -251,13 +251,12 @@ inline void IBMPC::isr(void)
     //       x  x  x  x    x  x  x  x | *1  0  0  0    0  0  0  0     midway(8 bits received)
     //      b6 b5 b4 b3   b2 b1 b0  1 |  0 *1  0  0    0  0  0  0     XT_IBM-midway ^1
     //      b7 b6 b5 b4   b3 b2 b1 b0 |  0 *1  0  0    0  0  0  0     AT-midway ^1
-    //      b7 b6 b5 b4   b3 b2 b1 b0 |  1 *1  0  0    0  0  0  0     XT_Clone-done ^3
-    //      b6 b5 b4 b3   b2 b1 b0  1 |  1 *1  0  0    0  0  0  0     XT_IBM-error ^3
+    //      b7 b6 b5 b4   b3 b2 b1 b0 |  1 *1  0  0    0  0  0  0     XT_Clone-done
     //      pr b7 b6 b5   b4 b3 b2 b1 |  0  0 *1  0    0  0  0  0     AT-midway[b0=0]
     //      b7 b6 b5 b4   b3 b2 b1 b0 |  1  0 *1  0    0  0  0  0     XT_IBM-done ^2
     //      pr b7 b6 b5   b4 b3 b2 b1 |  1  0 *1  0    0  0  0  0     AT-midway[b0=1] ^2
-    //      b7 b6 b5 b4   b3 b2 b1 b0 |  1  1 *1  0    0  0  0  0     XT_IBM-error-done
     //       x  x  x  x    x  x  x  x |  0  1 *1  0    0  0  0  0     illegal
+    //       x  x  x  x    x  x  x  x |  1  1 *1  0    0  0  0  0     illegal
     //      st pr b7 b6   b5 b4 b3 b2 | b1 b0  0 *1    0  0  0  0     AT-done
     //       x  x  x  x    x  x  x  x |  x  x  1 *1    0  0  0  0     illegal
     //                                all other states than above     illegal
@@ -273,34 +272,11 @@ inline void IBMPC::isr(void)
             // midway
             goto NEXT;
             break;
-        case 0b11000000:    // ^3
-            {
-                uint8_t us = 100;
-                // wait for rising and falling edge of b7 of XT_IBM
-                if (!protocol) {
-                    while (!(IBMPC_CLOCK_PIN & clock_mask) && us) { wait_us(1); us--; }
-                    while ( (IBMPC_CLOCK_PIN & clock_mask) && us) { wait_us(1); us--; }
-                } else if (protocol == IBMPC_PROTOCOL_XT_CLONE) {
-                    us = 0;
-                }
-
-                if (us) {
-                    // XT_IBM-error: read start(0) as 1
-                    goto NEXT;
-                } else {
-                    // XT_Clone-done
-                    isr_debug = isr_state;
-                    isr_state = isr_state>>8;
-                    protocol = IBMPC_PROTOCOL_XT_CLONE;
-                    goto DONE;
-                }
-            }
-            break;
-        case 0b11100000:
-            // XT_IBM-error-done
+        case 0b11000000:
+            // XT_Clone-done
             isr_debug = isr_state;
             isr_state = isr_state>>8;
-            protocol = IBMPC_PROTOCOL_XT_ERROR;
+            protocol = IBMPC_PROTOCOL_XT_CLONE;
             goto DONE;
             break;
         case 0b10100000:    // ^2
@@ -369,6 +345,7 @@ inline void IBMPC::isr(void)
             goto DONE;
             break;
         case 0b01100000:
+        case 0b11100000:
         case 0b00110000:
         case 0b10110000:
         case 0b01110000:
diff --git a/tmk_core/protocol/ibmpc.hpp b/tmk_core/protocol/ibmpc.hpp
index 7f94c140..960a980c 100644
--- a/tmk_core/protocol/ibmpc.hpp
+++ b/tmk_core/protocol/ibmpc.hpp
@@ -75,7 +75,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #define IBMPC_PROTOCOL_XT       0x20
 #define IBMPC_PROTOCOL_XT_IBM   0x21
 #define IBMPC_PROTOCOL_XT_CLONE 0x22
-#define IBMPC_PROTOCOL_XT_ERROR 0x23
 
 // Error numbers
 #define IBMPC_ERR_NONE        0