-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathDMG_ROM.asm
168 lines (148 loc) · 3.87 KB
/
DMG_ROM.asm
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
LD SP,$fffe ; $0000 Setup Stack
XOR A ; $0003 Zero the memory from $8000-$9FFF (VRAM)
LD HL,$9fff ; $0004
Addr_0007:
LD (HL-),A ; $0007
BIT 7,H ; $0008
JR NZ, Addr_0007 ; $000a
LD HL,$ff26 ; $000c Setup Audio
LD C,$11 ; $000f
LD A,$80 ; $0011
LD (HL-),A ; $0013
LD ($FF00+C),A ; $0014
INC C ; $0015
LD A,$f3 ; $0016
LD ($FF00+C),A ; $0018
LD (HL-),A ; $0019
LD A,$77 ; $001a
LD (HL),A ; $001c
LD A,$fc ; $001d Setup BG palette
LD ($FF00+$47),A ; $001f
LD DE,$0104 ; $0021 Convert and load logo data from cart into Video RAM
LD HL,$8010 ; $0024
Addr_0027:
LD A,(DE) ; $0027
CALL $0095 ; $0028
CALL $0096 ; $002b
INC DE ; $002e
LD A,E ; $002f
CP $34 ; $0030
JR NZ, Addr_0027 ; $0032
LD DE,$00d8 ; $0034 Load 8 additional bytes into Video RAM
LD B,$08 ; $0037
Addr_0039:
LD A,(DE) ; $0039
INC DE ; $003a
LD (HL+),A ; $003b
INC HL ; $003c
DEC B ; $003d
JR NZ, Addr_0039 ; $003e
LD A,$19 ; $0040 Setup background tilemap
LD ($9910),A ; $0042
LD HL,$992f ; $0045
Addr_0048:
LD C,$0c ; $0048
Addr_004A:
DEC A ; $004a
JR Z, Addr_0055 ; $004b
LD (HL-),A ; $004d
DEC C ; $004e
JR NZ, Addr_004A ; $004f
LD L,$0f ; $0051
JR Addr_0048 ; $0053
; === Scroll logo on screen, and play logo sound===
Addr_0055:
LD H,A ; $0055 Initialize scroll count, H=0
LD A,$64 ; $0056
LD D,A ; $0058 set loop count, D=$64
LD ($FF00+$42),A ; $0059 Set vertical scroll register
LD A,$91 ; $005b
LD ($FF00+$40),A ; $005d Turn on LCD, showing Background
INC B ; $005f Set B=1
Addr_0060:
LD E,$02 ; $0060
Addr_0062:
LD C,$0c ; $0062
Addr_0064:
LD A,($FF00+$44) ; $0064 wait for screen frame
CP $90 ; $0066
JR NZ, Addr_0064 ; $0068
DEC C ; $006a
JR NZ, Addr_0064 ; $006b
DEC E ; $006d
JR NZ, Addr_0062 ; $006e
LD C,$13 ; $0070
INC H ; $0072 increment scroll count
LD A,H ; $0073
LD E,$83 ; $0074
CP $62 ; $0076 $62 counts in, play sound #1
JR Z, Addr_0080 ; $0078
LD E,$c1 ; $007a
CP $64 ; $007c
JR NZ, Addr_0086 ; $007e $64 counts in, play sound #2
Addr_0080:
LD A,E ; $0080 play sound
LD ($FF00+C),A ; $0081
INC C ; $0082
LD A,$87 ; $0083
LD ($FF00+C),A ; $0085
Addr_0086:
LD A,($FF00+$42) ; $0086
SUB B ; $0088
LD ($FF00+$42),A ; $0089 scroll logo up if B=1
DEC D ; $008b
JR NZ, Addr_0060 ; $008c
DEC B ; $008e set B=0 first time
JR NZ, Addr_00E0 ; $008f ... next time, cause jump to "Nintendo Logo check"
LD D,$20 ; $0091 use scrolling loop to pause
JR Addr_0060 ; $0093
; ==== Graphic routine ====
LD C,A ; $0095 "Double up" all the bits of the graphics data
LD B,$04 ; $0096 and store in Video RAM
Addr_0098:
PUSH BC ; $0098
RL C ; $0099
RLA ; $009b
POP BC ; $009c
RL C ; $009d
RLA ; $009f
DEC B ; $00a0
JR NZ, Addr_0098 ; $00a1
LD (HL+),A ; $00a3
INC HL ; $00a4
LD (HL+),A ; $00a5
INC HL ; $00a6
RET ; $00a7
Addr_00A8:
;Nintendo Logo
.DB $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D
.DB $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99
.DB $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E
Addr_00D8:
;More video data
.DB $3C,$42,$B9,$A5,$B9,$A5,$42,$3C
; ===== Nintendo logo comparison routine =====
Addr_00E0:
LD HL,$0104 ; $00e0 ; point HL to Nintendo logo in cart
LD DE,$00a8 ; $00e3 ; point DE to Nintendo logo in DMG rom
Addr_00E6:
LD A,(DE) ; $00e6
INC DE ; $00e7
CP (HL) ; $00e8 ;compare logo data in cart to DMG rom
JR NZ,$fe ; $00e9 ;if not a match, lock up here
INC HL ; $00eb
LD A,L ; $00ec
CP $34 ; $00ed ;do this for $30 bytes
JR NZ, Addr_00E6 ; $00ef
LD B,$19 ; $00f1
LD A,B ; $00f3
Addr_00F4:
ADD (HL) ; $00f4
INC HL ; $00f5
DEC B ; $00f6
JR NZ, Addr_00F4 ; $00f7
ADD (HL) ; $00f9
JR NZ,$fe ; $00fa ; if $19 + bytes from $0134-$014D don't add to $00
; ... lock up
LD A,$01 ; $00fc
LD ($FF00+$50),A ; $00fe ;turn off DMG rom