work towards quote mode in MEGA65 screen editor

src/kernal/screen_m65/mega65_chrout_screen_control.s

@@ -75,8 +75,6 @@ m65_chrout_try_color_loop:
 
 // XXX: implement screen routines below:
 
-m65_chrout_screen_quote:
-	nop
 m65_chrout_screen_CLR:
 	nop
 m65_chrout_screen_HOME:
@@ -101,9 +99,11 @@ m65_chrout_screen_ESC:
 	nop
 m65_chrout_screen_BELL:
 	nop
-m65_chrout_screen_STOP:
-	nop
 m65_chrout_screen_DEL:
 	nop
+m65_chrout_screen_GFX:
+	nop
+m65_chrout_screen_TXT:
+	nop
 
 	jmp m65_chrout_screen_done

src/kernal/screen_m65/mega65_chrout_screen_control_2.s

@@ -41,18 +41,11 @@ m65_chrout_screen_SHIFT_OFF:
 	jmp_8 m65_chrout_screen_ctrl2_end
 
 
-// GFX/TXT switching support
+// STOP key support
 
-m65_chrout_screen_GFX:
+m65_chrout_screen_STOP:
 
-	lda VIC_YMCSB
+	lda #$00
-	and #$02 // to upper case
+	sta QTSW
-!:
+	sta INSRT
-	sta VIC_YMCSB
 	jmp_8 m65_chrout_screen_ctrl2_end
-
-m65_chrout_screen_TXT:
-
-	lda VIC_YMCSB
-	ora #$02    // to lower case
-	bne !-      // branch always

src/kernal/screen_m65/mega65_screen_quote.s

@@ -0,0 +1,23 @@
+
+// #LAYOUT# M65 KERNAL_1 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// CHROUT routine - screen support, control codes in quote mode, MEGA65 native mode version
+//
+
+
+m65_chrout_screen_quote:
+
+	// Low control codes are just +$80
+	clc
+	adc #$80
+
+	// If it overflowed, then it is a high control code,
+	// so we need to make it be $80 + $40 + char
+	// as we will have flipped back to just $00 + char, we should
+	// now add $c0 if C is set from overflow
+	bcc !+
+	adc #$BF    // C=1, so adding $BF + C = add $C0
+!:	
+	jmp m65_chrout_screen_literal