- db "Diagnostic ROM complete; flip switches to nonzero and then to zero to reset.",$0D,$0A,0
+ db "Diagnostic ROM complete; flip switches to nonzero and then to zero to reset. Expect A.",$0D,$0A,0
+
+testa:
+ ld c, $0F
+ ld a, [c]
+ ld b, $00
+ cp b
+ ret z
+ xor a
+ ld [c], a
+ ld hl, $D000
+ ld c, [hl]
+ inc bc
+ ld [hl], c
+ ld a, c
+ ld c, $50
+ ld [c], a
+ ret