git.joshuawise.com / fpgaboy.git / blame
| Commit | Line | Data |
|---|---|---|
| 6bd4619b JW |
1 | SECTION "a",HOME[$00] |
| 2 | ||
| 3 | LD SP,$fffe ; $0000 Setup Stack | |
| 4 | ||
| 5 | XOR A ; $0003 Zero the memory from $8000-$9FFF (VRAM) | |
| 6 | LD HL,$9fff ; $0004 | |
| 7 | Addr_0007: | |
| 8 | LD [HLD],A ; $0007 | |
| 9 | BIT 7,H ; $0008 | |
| 10 | JR NZ, Addr_0007 ; $000a | |
| 11 | ||
| 12 | LD HL,$ff26 ; $000c Setup Audio | |
| 13 | LD C,$11 ; $000f | |
| 14 | LD A,$80 ; $0011 | |
| 15 | LD [HLD],A ; $0013 | |
| 16 | LD [C],A ; $0014 | |
| 17 | INC C ; $0015 | |
| 18 | LD A,$f3 ; $0016 | |
| 19 | LD [C],A ; $0018 | |
| 20 | LD [HLD],A ; $0019 | |
| 21 | LD A,$77 ; $001a | |
| 22 | LD [HLD],A ; $001c | |
| 23 | ||
| 24 | LD A,$fc ; $001d Setup BG palette | |
| 25 | LD [$FF47],A ; $001f | |
| 26 | ||
| 27 | LD DE,$0104 ; $0021 Convert and load logo data from cart into Video RAM | |
| 28 | LD HL,$8010 ; $0024 | |
| 29 | Addr_0027: | |
| 30 | LD A,[DE] ; $0027 | |
| c279b666 JW |
31 | CALL a95 ; $0028 |
| 32 | CALL a96 ; $002b | |
| 6bd4619b JW |
33 | INC DE ; $002e |
| 34 | LD A,E ; $002f | |
| 35 | CP $34 ; $0030 | |
| 36 | JR NZ, Addr_0027 ; $0032 | |
| 37 | ||
| 38 | LD DE,$00d8 ; $0034 Load 8 additional bytes into Video RAM | |
| 39 | LD B,$08 ; $0037 | |
| 40 | Addr_0039: | |
| 41 | LD A,[DE] ; $0039 | |
| 42 | INC DE ; $003a | |
| 43 | LD [HLI],A ; $003b | |
| 44 | INC HL ; $003c | |
| 45 | DEC B ; $003d | |
| 46 | JR NZ, Addr_0039 ; $003e | |
| 47 | ||
| 48 | LD A,$19 ; $0040 Setup background tilemap | |
| 49 | LD [$9910],A ; $0042 | |
| 50 | LD HL,$992f ; $0045 | |
| 51 | Addr_0048: | |
| 52 | LD C,$0c ; $0048 | |
| 53 | Addr_004A: | |
| 54 | DEC A ; $004a | |
| 55 | JR Z, Addr_0055 ; $004b | |
| 56 | LD [HLD],A ; $004d | |
| 57 | DEC C ; $004e | |
| 58 | JR NZ, Addr_004A ; $004f | |
| 59 | LD L,$0f ; $0051 | |
| 60 | JR Addr_0048 ; $0053 | |
| 61 | ||
| 62 | ; === Scroll logo on screen, and play logo sound=== | |
| 63 | ||
| 64 | Addr_0055: | |
| 65 | LD H,A ; $0055 Initialize scroll count, H=0 | |
| 66 | LD A,$64 ; $0056 | |
| 67 | LD D,A ; $0058 set loop count, D=$64 | |
| 68 | LD [$FF42],A ; $0059 Set vertical scroll register | |
| 69 | LD A,$91 ; $005b | |
| 70 | LD [$FF40],A ; $005d Turn on LCD, showing Background | |
| 71 | INC B ; $005f Set B=1 | |
| 72 | Addr_0060: | |
| 73 | LD E,$02 ; $0060 | |
| 74 | Addr_0062: | |
| 75 | LD C,$0c ; $0062 | |
| 76 | Addr_0064: | |
| 77 | LD A,[$FF44] ; $0064 wait for screen frame | |
| 78 | CP $90 ; $0066 | |
| 79 | JR NZ, Addr_0064 ; $0068 | |
| 80 | DEC C ; $006a | |
| 81 | JR NZ, Addr_0064 ; $006b | |
| 82 | DEC E ; $006d | |
| 83 | JR NZ, Addr_0062 ; $006e | |
| 84 | ||
| 85 | LD C,$13 ; $0070 | |
| 86 | INC H ; $0072 increment scroll count | |
| 87 | LD A,H ; $0073 | |
| 88 | LD E,$83 ; $0074 | |
| 89 | CP $62 ; $0076 $62 counts in, play sound #1 | |
| 90 | JR Z, Addr_0080 ; $0078 | |
| 91 | LD E,$c1 ; $007a | |
| 92 | CP $64 ; $007c | |
| 93 | JR NZ, Addr_0086 ; $007e $64 counts in, play sound #2 | |
| 94 | Addr_0080: | |
| 95 | LD A,E ; $0080 play sound | |
| 96 | LD [C],A ; $0081 | |
| 97 | INC C ; $0082 | |
| 98 | LD A,$87 ; $0083 | |
| 99 | LD [C],A ; $0085 | |
| 100 | Addr_0086: | |
| 101 | LD A,[$FF42] ; $0086 | |
| 102 | SUB B ; $0088 | |
| 103 | LD [$FF42],A ; $0089 scroll logo up if B=1 | |
| 104 | DEC D ; $008b | |
| 105 | JR NZ, Addr_0060 ; $008c | |
| 106 | ||
| 107 | DEC B ; $008e set B=0 first time | |
| 108 | JR NZ, Addr_00E0 ; $008f ... next time, cause jump to "Nintendo Logo check" | |
| 109 | ||
| 110 | LD D,$20 ; $0091 use scrolling loop to pause | |
| 111 | JR Addr_0060 ; $0093 | |
| 112 | ||
| 113 | ; ==== Graphic routine ==== | |
| 114 | ||
| c279b666 JW |
115 | a95: LD C,A ; $0095 "Double up" all the bits of the graphics data |
| 116 | a96: LD B,$04 ; $0096 and store in Video RAM | |
| 6bd4619b JW |
117 | Addr_0098: |
| 118 | PUSH BC ; $0098 | |
| 119 | RL C ; $0099 | |
| 120 | RLA ; $009b | |
| 121 | POP BC ; $009c | |
| 122 | RL C ; $009d | |
| 123 | RLA ; $009f | |
| 124 | DEC B ; $00a0 | |
| 125 | JR NZ, Addr_0098 ; $00a1 | |
| 126 | LD [HLI],A ; $00a3 | |
| 127 | INC HL ; $00a4 | |
| 128 | LD [HLI],A ; $00a5 | |
| 129 | INC HL ; $00a6 | |
| 130 | RET ; $00a7 | |
| 131 | ||
| 132 | Addr_00A8: | |
| 133 | ;Nintendo Logo | |
| 134 | DB $CE,$ED,$66,$66,$CC,$0D,$00,$0B,$03,$73,$00,$83,$00,$0C,$00,$0D | |
| 135 | DB $00,$08,$11,$1F,$88,$89,$00,$0E,$DC,$CC,$6E,$E6,$DD,$DD,$D9,$99 | |
| 136 | DB $BB,$BB,$67,$63,$6E,$0E,$EC,$CC,$DD,$DC,$99,$9F,$BB,$B9,$33,$3E | |
| 137 | ||
| 138 | Addr_00D8: | |
| 139 | ;More video data | |
| 140 | DB $3C,$42,$B9,$A5,$B9,$A5,$42,$3C | |
| 141 | ||
| 142 | ; ===== Nintendo logo comparison routine ===== | |
| 143 | ||
| 144 | Addr_00E0: | |
| 145 | LD HL,$0104 ; $00e0 ; point HL to Nintendo logo in cart | |
| 146 | LD DE,$00a8 ; $00e3 ; point DE to Nintendo logo in DMG rom | |
| 147 | ||
| 148 | Addr_00E6: | |
| 149 | LD A,[DE] ; $00e6 | |
| 150 | INC DE ; $00e7 | |
| 151 | CP [HL] ; $00e8 ;compare logo data in cart to DMG rom | |
| 152 | .fuq JR NZ,.fuq ; $00e9 ;if not a match, lock up here | |
| 153 | INC HL ; $00eb | |
| 154 | LD A,L ; $00ec | |
| 155 | CP $34 ; $00ed ;do this for $30 bytes | |
| 156 | JR NZ, Addr_00E6 ; $00ef | |
| 157 | ||
| 158 | LD B,$19 ; $00f1 | |
| 159 | LD A,B ; $00f3 | |
| 160 | Addr_00F4: | |
| 161 | ADD [HL] ; $00f4 | |
| 162 | INC HL ; $00f5 | |
| 163 | DEC B ; $00f6 | |
| 164 | JR NZ, Addr_00F4 ; $00f7 | |
| 165 | ADD [HL] ; $00f9 | |
| 166 | .fuq: JR NZ,.fuq ; $00fa ; if $19 + bytes from $0134-$014D don't add to $00 | |
| 167 | ; ... lock up | |
| 168 | ||
| 169 | LD A,$01 ; $00fc | |
| 170 | LD [$FF50],A ; $00fe ;turn off DMG rom |