Patch for TMK firmware to work with old BTC keyboard (XT protocol)

TMK_BTC_Keyboard.patch

diff --git a/converter/xt_usb/Makefile b/converter/xt_usb/Makefile
index 395115e..a798490 100644
--- a/converter/xt_usb/Makefile
+++ b/converter/xt_usb/Makefile
@@ -70,7 +70,7 @@ F_USB = $(F_CPU)
 #   Atmel DFU loader 4096
 #   LUFA bootloader  4096
 #   USBaspLoader     2048
-OPT_DEFS += -DBOOTLOADER_SIZE=512
+OPT_DEFS += -DBOOTLOADER_SIZE=4096
 
 
 # Build Options
diff --git a/converter/xt_usb/led.c b/converter/xt_usb/led.c
index 8eaa88b..4e507c3 100644
--- a/converter/xt_usb/led.c
+++ b/converter/xt_usb/led.c
@@ -1,3 +1,4 @@
+#include <util/delay.h>
 /*
 Copyright 2016 Ethan Apodaca <papodaca@gmail.com>
 
@@ -16,5 +17,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 void led_set(uint8_t usb_led) {
-  //XT Keyboards do not have LEDs, nothing to do.
+    PORTF = ((~((usb_led << 6) & 0x40)) & (~((usb_led << 4) & 0x20)) & (~((usb_led << 2) & 0x10))) & 0x70;
+    PORTF |= 0x80;
+    _delay_ms(1);
+    PORTF ^= 0x80;
 }
+
diff --git a/converter/xt_usb/matrix.c b/converter/xt_usb/matrix.c
index 51742dd..d0ff8e2 100644
--- a/converter/xt_usb/matrix.c
+++ b/converter/xt_usb/matrix.c
@@ -45,7 +45,8 @@ void matrix_init(void)
 
     // initialize matrix state: all keys off
     for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
-
+    // LED's
+    DDRF = 0xF0;
     return;
 }
 
@@ -112,7 +113,8 @@ uint8_t matrix_scan(void)
         E1_1D_45_E1_9D,
         // pause
     } state = INIT;
-
+    
+    static int processing = 0;
 
     // 'pseudo break code' hack
     if (matrix_is_on(ROW(PAUSE), COL(PAUSE))) {
@@ -120,14 +122,20 @@ uint8_t matrix_scan(void)
     }
 
     uint8_t code = xt_host_recv();
+    // if we waiting for sequence, then wait.
+    if (!code && processing) {
+        return 1;
+    }
     switch (state) {
         case INIT:
             switch (code) {
                 case 0xE0:
                     state = E0;
+                    processing = 1;
                     break;
                 case 0xE1:
                     state = E1;
+                    processing = 1;
                     break;
                 default:    // normal key make
                     if (code < 0x80 && code != 0x00) {
@@ -138,15 +146,18 @@ uint8_t matrix_scan(void)
                         matrix_break(code - 0x80);
                     }
                     state = INIT;
+                    processing = 0;
             }
             break;
         case E0:    // E0-Prefixed
             switch (code) { //move these codes to unused places on the matrix
                 case 0x2A:
                     state = E0_2A;
+                    processing = 1;
                     break;
                 case 0xB7:
                     state = E0_B7;
+                    processing = 1;
                     break;
                 default:
                     if (code < 0x80 && code != 0x00) {
@@ -155,64 +166,87 @@ uint8_t matrix_scan(void)
                         matrix_break(move_codes(code - 0x80));
                     }
                     state = INIT;
+                    processing = 0;
             }
             break;
         case E0_2A:
-            if(code == 0xE0)
+            if(code == 0xE0) {
                 state = E0_2A_E0;
-            else
+                processing = 1;
+            } else {
                 state = INIT;
+                processing = 0;
+            }
             break;
         case E0_2A_E0:
             if(code == 0x37)
                 matrix_make(PRINT_SCREEN);
             else
                 state = INIT;
+            processing = 0;
             break;
         case E0_B7:
-            if(code == 0xE0)
-                state = E0_B7;
-            else
+            if(code == 0xE0) {
+                state = E0_B7_E0;
+                processing = 1;
+            } else {
                 state = INIT;
+                processing = 0;
+            }
             break;
         case E0_B7_E0:
           if(code == 0xAA)
               matrix_break(PRINT_SCREEN);
           else
               state = INIT;
+          processing = 0;
           break;
         case E1:
-            if (code == 0x1D)
+            if (code == 0x1D) {
                 state = E1_1D;
-            else
+                processing = 1;
+            } else {
                 state = INIT;
+                processing = 0;
+            }
             break;
         case E1_1D:
-            if(code == 0x45)
+            if(code == 0x45) {
                 state = E1_1D_45;
-            else
+                processing = 1;
+            } else {
                 state = INIT;
+                processing = 0;
+            }
             break;
         case E1_1D_45:
-            if(code == 0xE1)
+            if(code == 0xE1) {
                 state = E1_1D_45_E1;
-            else
+                processing = 1;
+            } else {
                 state = INIT;
+                processing = 0;
+            }
             break;
         case E1_1D_45_E1:
-            if(code == 0x9D)
+            if(code == 0x9D) {                
                 state = E1_1D_45_E1_9D;
-            else
+                processing = 1;
+            } else {
                 state = INIT;
+                processing = 0;
+            }
             break;
         case E1_1D_45_E1_9D:
             if(code == 0xC5)
                 matrix_make(PAUSE);
             else
                 state = INIT;
+            processing = 0;
             break;
         default:
             state = INIT;
+            processing = 0;
     }
     return 1;
 }
diff --git a/tmk_core/protocol/xt_interrupt.c b/tmk_core/protocol/xt_interrupt.c
index 94b47db..c06d09b 100644
--- a/tmk_core/protocol/xt_interrupt.c
+++ b/tmk_core/protocol/xt_interrupt.c
@@ -78,17 +78,11 @@ ISR(XT_INT_VECT)
         if (data_in())
             data |= 0x80;
         if (state == 8)
-            goto END;
+            pbuf_enqueue(data);
         state++;
     } else {
-        goto DONE;
+        state = 0;
+        data = 0;
     }
-    goto RETURN;
-END:
-    pbuf_enqueue(data);
-DONE:
-    state = 0;
-    data = 0;
-RETURN:
     return;
 }