;;
;; Official Kernal routine, described in:
;;
;; - [RG64] C64 Programmer's Reference Guide   - page 292
;; - [CM64] Compute's Mapping the Commodore 64 - page 239
;;
;; CPU registers that has to be preserved (see [RG64]): .X, .Y
;;

readst:

	;; Check the current device number

	lda current_device_number
	cmp #$02
	bne +
	
	;; This is RS-232 device - according to 'Compute's Mapping the Commodore 64' page 239
	;; it reads status from RSSTAT
	lda RSSTAT
	rts
*
	;; According to 'Compute's Mapping the Commodore 64' page 239, it usually retrieves
	;; status from IOSTATUS
	
	;; XXX is it always the case if device is not RS-232 ?

	lda IOSTATUS
	rts