initial support for Mega65 extra ROM

c64/kernal/interrupts/fe66.default_brk_handler.s

@@ -1,9 +1,10 @@
+#if ROM_LAYOUT_STD || (ROM_LAYOUT_M65 && SEGMENT_KERNAL_0)
 
 default_brk_handler:
 
-	// Implemented according to Compute's Mapping the Commodore 64, pages 73-74
+	// Implemented according to Computes Mapping the Commodore 64, pages 73-74
 
-	sei // disable IRQs, to be sure they won't interfere
+	sei // disable IRQs, to be sure they wont interfere
 
 	ldx #$00
 	sta VIC_SCROLX // turn the display off - we want as little screen artifacts as possible
@@ -13,8 +14,8 @@ default_brk_handler:
 	jsr JRESTOR
 	jsr JIOINIT
 
-	// Original routine calls just a part of CINT - but I'm not sure which one. Most likely it
-	// skips the PAL/NTSC check by calling $E518. I suspect bug in the original ROM, let's
+	// Original routine calls just a part of CINT - but I am not sure which one. Most likely it
+	// skips the PAL/NTSC check by calling $E518. I suspect bug in the original ROM, lets
 	// call the whole CINT, just to be sure everything is initialized.
 
 	jsr CINT
@@ -22,3 +23,6 @@ default_brk_handler:
 	cli
 
 	jmp (IBASIC_WARM_START)
+
+
+#endif // ROM layout