BYTE 5.1 PG 56 A computer controlled light dimmer Part 1
BYTE 5.2 PG 72 A computer controlled light dimmer Part 2
BYTE 4.10 PG 202


addr	value of address label or absolute address
adrr	=addr-2-PC, relitive address
im	byte immediate
fp	byte offset in first page memory
imwd	=im,im word immediate
xx	=im index offset
a	accumulator registor
 0 A
 1 B
mm	memory address mode
 00 immediate	op #<immediate value>
 01 first page	op <address in first page>
 10 index	op <offset>,X
 11 absolute	op <absolute address>
d	direction 
 0 load 
 1 store
maop	Math Operation
 0000 SUB
 0001 CMP
 0100 AND
 0101 BIT
 0110 LDA
 0111 STA
 1000 EOR
 1001 ADC
 1010 ORA
 1011 ADD
 1100 CPX


PC	program counter register
A	First accumulator register
B	second accumulator register
X	index register
P	CCR Condition Code Register
 H	 Half carry	5
 I	 Interrupt mask	4
 N	 Negative	3
 Z	 Zero		2
 V	 oVerflow	1
 C	 Carry		0
S	Stack pointer register


01	NOP
02
03
04
05
06	TAP		;P=A	Transfer to CCR
07	TPA		;A=P	Transfer from CCR
08	INX		;Increment X, Compare with 0?
09	DEX		;Decrement X, Compare with 0?
0A	CLV		;Clear Overflow
0B	SEV		;Set Overflow
0C	CLC		;Clear Carry
0D	SEC		;Set Carry
0E	CLI		;Clear IRQ Mask
0F	SEI		;Set IRQ Mask

16	TAB		;Transfer A to B?
17	TBA		;Transfer B to A
18			;?
19	DAA		;Decimal adjust accumulator
1B	ABA		;A=A+B Add accumulators

20 ar	BRA adrr	;	Skip (Branch Always)
21 ar	BRN adrr	;	Branch Never
22 ar	BHI adrr	;C|Z=0? Branch Higher
23 ar	BLS adrr	;C|Z=1? Branch Lower or Same
24 ar	BCC adrr	;C=0? 	Branch Carry Clear
25 ar	BCS adrr	;C=1? 	Branch Carry Set
26 ar	BNE adrr	;Z=1? 	Branch Not Equal
27 ar	BEQ adrr	;Branch Equal
28 ar	BVC adrr	;Branch oVerflow Clear
29 ar	BVS adrr	;Branch Half Carry Set
2A ar	BPL adrr	;N=0? 	Branch Plus
2B ar	BM1 adrr	;N=1?	Branch Minus
2C ar	BGE adrr	;N^V=0?	Branch Greater than or Equal
2D ar	BLT adrr	;N^V=1?	Branch Less Than
2E ar	BGT adrr	;Z|{N^V}=0? !Z&!{N^V}=1? Branch Greater than
2F ar	BLE adrr	;Z|{N^V}=1?	Branch Less than or Equal


32	PUL	A
33	PUL	B
34	DES		;Decrement Stack, Compare with 0?
35
36	PSH	A
37	PSH	B
38

39	RTS		;RETURN
3A
3B	RTI		;Return from interrupt?


80 12	SUB A	#18
90
A0
B0


81 im	CMP A im
91 fp	CMP A fp	
A1 xx	CMP A xx,X
B1 addr CMP A addr
C1 im	CMP B im
D1 fp	CMP B fp
E1 xx	CMP B xx,X
F1 addr	CMP B addr


 1amm 0100
84 im	AND A im	;A=A&im     And A with immediate byte
94 fp	AND A fp	;A=A&(fp)   And A with first page memory byte at immediate byte
A4 xx	AND A xx,X	;A=A&(xx+X) And A with memory byte at X+byte offset
B4 addr	AND A addr	;A=A&(addr) And A with memory byte at addr
C4 im	AND B im	;B=B&im     And B with immediate byte
D4 fp	AND B fp	;B=B&(fp)   And B with first page memory byte at immediate byte
E4 xx	AND B xx,X	;B=B&(xx+X) And B with memory byte at X+byte offset
F4 addr	AND B addr	;B=B&(addr) And B with memory byte at addr


 1amm 0101
85 im	BIT A im	;A&im	  Bit test
95 fp	BIT A fp	;A&(fp)	  
A5 xx	BIT A xx,X	;A&(xx+X) 
B5 addr	BIT A addr	;A&(addr) 
C5 im	BIT B im	;B&im	  
D5 fp	BIT B fp	;B&(fp)	  
E5 xx	BIT B xx,X	;B&(xx+X) 
F5 addr	BIT B addr	;B&(addr) 

 1amm 011d		; Load Accumulator register
86 3F	LDA A	#$3F	;Load A byte immediate
96 20	LDA A	RNDM	;Load A with byte memory at first page address byte immediate
A6 00	LDA A	0,X	;Load A with byte memory at X+byte immediate
B6 A000	LDA A	ASSA	;Load A with byte memory at word immediate
C6 18	LDA B	$24	;Load B byte immediate (24d is 18h)
D6 20	LDA B	RNDM	;Load B with byte memory at first page address byte immediate
E6 00	LDA B	0,X	;Load B with byte memory at X+byte immediate
F6 A000	LDA B	ASSA	;Load B with byte memory at word immediate

87			; not used?
97 22	STA A	RNDM+2	;Store A in first page memory address byte immediate (RNDM is at address 20 in first page)
A7 00	STA A	0,X	;Store A in memory at X+byte immediate
B7			; not used?
C7			; not used?
D7 22	STA B	RNDM+2	;Store B in first page memory address byte immediate (RNDM is at address 20 in first page)
E7 02	STA B	2,X	;Store B in memory at X+byte immediate
F7			; not used?

88
98 20	EOR	A	RNDM	;XOR
A8
B8
C8
D8
E8
F8

 1amm 1001
89 im	ADC A im	;A=A+im+C     Add A with Carry to immediate byte
99 fp	ADC A fp	;A=A+(fp)+C   Add A with Carry to first page memory byte at immediate byte
A9 xx	ADC A xx,X	;A=A+(xx+X)+C Add A with Carry to memory byte at X+byte offset
B9 addr	ADC A addr	;A=A+(addr)+C Add A with Carry to memory byte at addr
C9 im	ADC B im	;B=B+im+C     Add B with Carry to immediate byte
D9 fp	ADC B fp	;B=B+(fp)+C   Add B with Carry to first page memory byte at immediate byte
E9 xx	ADC B xx,X	;B=B+(xx+X)+C Add B with Carry to memory byte at X+byte offset
F9 addr	ADC B addr	;B=B+(addr)+C Add B with Carry to memory byte at addr

 1amm 1010
8A im	ORA A im	;A=A|im     ORA with byte immediate
9A fp	ORA A fp	;A=A|(fp)   ORA with byte in first page address
AA xx	ORA A xx,X	;A=A|(xx+X) ORA with byte at X+byte offset
BA addr ORA A addr	;A=A|(addr) ORA with byte at memory address word immediate
CA im	ORA B im	;B=B|im     ORB with byte immediate
DA fp	ORA B fp	;B=B|(fp)   ORB with byte in first page address
EA xx	ORA B xx,X	;B=B|(xx+X) ORB with byte at X+byte offset
FA addr ORA B addr	;B=B|(addr) ORB with byte at memory address word immediate

 1amm 1011
8B im	ADD A im	;A=A+im     Add A to immediate byte
9B fp	ADD A fp	;A=A+(fp)   Add A to first page memory byte at immediate byte
AB xx	ADD A xx,X	;A=A+(xx+X) Add A to memory byte at X+byte offset
BB addr	ADD A addr	;A=A+(addr) Add A to memory byte at addr
CB im	ADD B im	;B=B+im     Add B to immediate byte
DB fp	ADD B fp	;B=B+(fp)   Add B to first page memory byte at immediate byte
EB xx	ADD B xx,X	;B=B+(xx+X) Add B to memory byte at X+byte offset
FB addr	ADD B addr	;B=B+(addr) Add B to memory byte at addr


8C 0013	CPX 	#$13		;
9C 75	CPX	SaveSum		;SaveSum equates to 75
AC
BC
CC
DC
EC
FC


8D os	BSR <PC-addr>	;(S--)=PC, PC=PC+2+os Branch to Service Routine at PC+offset+2
9D			;?
AD xx	JSR xx,X	;(S--)=PC, PC=X+xx Jump to Service Routine at indeX plus immediate byte
BD 012C	JSR addr RANDOM	;(S--)=PC, PC=addr Jump to Service Routine at immediate word (CALL) RANDOM is at address 012C

CD
DD
ED
FD

 1pmm 111d ; Load Pointer register p=Stack/Index mm=Immediate/FirstPage/Index/Address d=Load/Store
8E 8004	LDS	#PIAD	;Load Stack pointer with immediate word
9E 56	LDS fp	WTBLRP	;Load Stack pointer with first page memory word at byte immediate
AE xx	LDS xx,X	;Load Stack pointer with memory word at indeX plus byte immediate
BE A000 LDS addr ASSA	;Load Stack pointer with memory word at word immediate
CE 8004	LDX	#PIAD	;Load indeX with immediate word
DE 23	LDX fp	TBLADR	;Load indeX with word memory at byte immediate in first page (TBLADR is at address 0023 in first page)
EE xx	LDX xx,X	;Load indeX with word memory at indeX plus byte immediate
FE A000	LDX addr ASSA	;Load indeX with word memory at word immediate

8F	STS	      ?	;
9F 56	STS fp	WTBLRP 	;Store Stack pointer in first page memory address byte immediate (WTBLRP is at address 56 in first page)
AF xx	STS xx,X	;Store Stack pointer in memory word at indeX plus byte immediate
BF addr	STS addr	;Store Stack pointer in memory word at word immediate
CF 8004	STX	#PIAD ?	;
DF 23	STX fp	TBLADR	;Store indeX in memory word at first page memory address plus byte immediate (TBLADR is at address 23 in first page)
EF xx	STX xx,X	;Store indeX in memory word at indeX plus byte immediate
FF A000	STX addr ASSA	;Store indeX in memory word at word immediate


40	NEG A	;?
50 	NEG B
60
70


41
51
61
71


42
52
62
72


43	COM	A	;Complement A
53
63
73 44	COM	MPTPAT


44	LSR A		;Logical Shift Right
54	LSR B		;Shift right
64 xx	LSR xx,X
74 addr	LSR addr


45	ASR A		;Arithmetic Shift Right
55	ASR B
65 xx	ASR xx,X
75 addr ASR addr


46	ROR 	A
56	ROR 	B
66 00	ROR	0,X
76 0022	ROR	RNDM+2


47	ASR A		;A=A/2		Arithmetic Shift Right
57	ASR B		;B=B/2
67 xx	ASR xx,X	;(xx+X)=(xx+X)/2
77 addr	ASR addr	;(addr)=(addr)/2


48	ASL A		;A=A*2		Arithmetic Shift Left
58	ASL B		;B=B*2
68 xx	ASL xx,X	;(xx+X)=(xx+X)*2
78 addr ASL addr	;(addr)=(addr)*2


49	ROL A		;A=A<<
59	ROL B
69 xx	ROL xx,X
79 addr	ROL addr


4A	DEC	A
5A	DEC	B
6A 02	DEC	2,X
7A XXXX	DEC	(XXXX)		;?


4B
5B
6B
7B


4C	INC	A		;?
5C	INC	B
6C 02	INC	2,X
7C 8006	INC	PIA


4D	TST	A		;
5D	TST	B		;
6D 02	TST	2,X		;
7D XXXX	TST	(XXXX)		;GOOD


4E
5E
6E
7E 0100	JMP	START


4F	CLR A
5F	CLR B
6F 02	CLR	2,X	;
7F 49	CLR	ENDGAM	;ENDGAM is at 49 in first page

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