
(hlp) = (hlp) - A
-----------------------------

	eor #$ff
	sec
	adc hlp
	sta hlp
	scs
	dec hlp+1


(hlp) = (hlp) - A - 1
-----------------------------

	eor #$ff
	clc
	adc hlp
	sta hlp
	scs
	dec hlp+1

