Apple II manual Mask

	57	A2L	EQU	$3E
	58	A2H	EQU	$3F
	59	A3L	EQU	$40
	60	A3H	EQU	$41
	61	A4L	EQU	$42
	62	A4H	EQU	$43
	63	A5L	EQU	$44
	64	A5H	EQU	$45
	65	ACC	EQU	$45
	66	XREG	EQU	$46
	67	YREG	EQU	$47
	68	STATUS	EQU	$48
	69	SPNT	EQU	$49
	70	RNDL	EQU	$4E
	71	RNDH	EQU	$4F
	72	ACL	EQU	$50
	73	ACH	EQU	$51
	74	XTNDL	EQU	$52
	75	XTNDH	EQU	$53
	76	AUXL	EQU	$54
	77	AUXH	EQU	$55
	78	PICK	EQU	$95
	79	IN	EQU	$0200
	80	USRADR	EQU	$03F8
	81	NMI	EQU	$03FB
	82	IRQLOC	EQU	$03FE
	83	IOADR	EQU	$C000
	84	KBD	EQU	$C000
	85	KBDSTRB	EQU	$C010
	86	TAPEOUT	EQU	$C020
	87	SPKR	EQU	$C030
	88	TXTCLR	EQU	$C050
	89	TXTSET	EQU	$C051
	90	MIXCLR	EQU	$C052
	91	MIXSET	EQU	$C053
	92	LOWSCR	EQU	$C054
	93	HISCR	EQU	$C055
	94	LORES	EQU	$C056
	95	HIRES	EQU	$C057
	96	TAPEIN	EQU	$C060
	97	PADDL0	EQU	$C064
	98	PTRIG	EQU	$C070
	99	BASIC	EQU	$E000
	100	BASIC2	EQU	$E003
	101		ORG	$F800	;ROM START ADDRESS
F800: 4A	102	PLOT	LSR		;Y-COORD/2
F801: 08	103		PHP		;SAVE LSB IN CARRY
F802: 20 47 F8	104		JSR	GBASCALC	;CALC BASE ADR IN GBASL,H
F805: 28	105		PLP		;RESTORE LSB FROM CARRY
F806: A9 0F	106		LDA	#$0F	;MASK $0F IF EVEN
F808: 90 02	107		BCC	RTMASK
F80A: 69 E0	108		ADC	#$E0	;MASK $F0 IF ODD
F80C: 85 2E	109	RTMASK	STA	MASK
F80E: B1 26	110	PLOT1	LDA	(GBASL),Y	;DATA
F810: 45 30	111		EOR	COLOR	; EOR COLOR
F812: 25 2E	112		AND	MASK	;	AND MASK
F814: 51 26	113		EOR	(GBASL),Y	;	EOR DATA
F816: 91 26	114		STA	(GBASL),Y	;	TO DATA
F818: 60	115		RTS
F819: 20 00 F8	116	HLINE	JSR	PLOT	;PLOT SQUARE
F81C: C4 2C	117	HLINE1	CPY	H2	;DONE?
F81E: B0 11	118		BCS	RTS1	; YES, RETURN