Complete redesign of the CBM610 support.

Use wrappers to call the kernal in bank 15 instead of implementing kernal
functionality within the cc65 libs (eats performance but is much smaller and
simpler).
Improved startup/shutdown code allows a return to the system bank without
calling the BASIC cold start vector.


git-svn-id: svn://svn.cc65.org/cc65/trunk@2793 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm610/break.s

@@ -7,7 +7,7 @@
 
        	.export	      	_set_brk, _reset_brk
        	.export	       	_brk_a, _brk_x, _brk_y, _brk_sr, _brk_pc
-	.import	      	_atexit
+	.import	      	_atexit, BRKVec
 
 	.include	"cbm610.inc"
 
@@ -74,6 +74,8 @@ L1:	lda	#<brk_handler	; Set the break vector to our routine
 
 .proc	brk_handler
 
+        pla
+	sta	_brk_01
 	pla
 	sta	_brk_y
 	pla
@@ -90,15 +92,11 @@ L1:	lda	#<brk_handler	; Set the break vector to our routine
 	pla	    	 	; PC high
 	sbc	#0
 	sta	_brk_pc+1
-	lda	IndReg
-	sta	_brk_01
-	lda	ExecReg
-	sta	IndReg
 
 	jsr	uservec	 	; Call the user's routine
 
 	lda	_brk_01
-	sta	IndReg
+        sta     IndReg
 
 	lda	_brk_pc+1
 	pha