improved tape support with Mega65 native mode

src/kernal/extapi_m65/mega65_mode65.s

@@ -21,10 +21,19 @@ M65_MODE65:
 	lda #$35 // '5'
 	sta M65_MAGICSTR+2
 
+	// XXX find a better place for code below
+
 	// Switch VIC to VIC-IV mode
 
 	jsr viciv_unhide
 
+	// Disable badlines and slow interrupt emulation
+
+	lda #$00
+	sta MISC_EMU
+
+	// XXX
+
 	// Set screen mode to 80x25
 
 	lda #$01