====== Method used in "Mathematica" by Reflex ======

<code>
;;;;;
;;;;  detecting sid type (disassembled from Mathematica by Reflex)
;;;
;;    commented and labelled by Raf/Vulture Design
;
	; subroutine filling SID's registers with $00

        LDX #24
        LDA #0
loop    STA $D400,x
        DEX
        BPL loop

	; main routine
        LDA #$02
	STA $D40F
	LDA #$30
	STA $D412
	LDY #$00
	LDX #$00
sl3	LDA $D41B
	BMI sl2
	DEX
	BNE sl3
	DEY
	BNE sl3
	BEQ sl4
sl2	LDX #$01 	; 1 = 8580
sl4			; 0 = 6581
	bne d8580

; we have 6581 found
;	lda #<t6581 ; pointer to text about 6581
;	ldy #>t6581
;	jsr $ab1e

	jmp _end

; we have 8580 found
d8580 	
;       lda #<t8580 ; pointer to text about 8580
;	ldy #>t8580
;	jsr $ab1e
	
_end

</code>