switching from MEGA65 native mode to legacy mode works now

src/kernal/extapi_m65/mega65_mode64.s

@@ -8,8 +8,6 @@ M65_MODE64:
 
 	sei
 
-	// XXX provide full implementation - switch back to normal text mode
-
 	// Set the magic string to mark legacy mode
 
 	lda #$00
@@ -17,19 +15,10 @@ M65_MODE64:
 	sta M65_MAGICSTR+1
 	sta M65_MAGICSTR+2
 
-	// Reenable badlines and slow interrupt emulation
+	// Restore VIC-II configuration
 
-	lda #$03
-	sta MISC_EMU
-
-	// Set misc VIC-IV flags
-
-	lda %00000000  // enable C64 character set
-	sta VIC_CTRLA
-
-	// Switch to VIC-II mode
-
-	sta VIC_KEY
+	jsr viciv_shutdown
+	jsr setup_vicii
 
 	// Reenable interrupts