Notes:Gon

This page contains notes for the game Gon.

Stage Select and Sound Test

$80/A1DB AD 82 10    LDA $1082  [$80:1082]
$80/A1DE 8D 86 10    STA $1086  [$80:1086]
$80/A1E1 4C EA A1    JMP $A1EA  [$80:A1EA]   //jumps over the stage select and sound test programming...

$80/A1E4 A9 B6 FC    LDA #$FCB6              //pointer to stage select and sound test
$80/A1E7 20 87 88    JSR $8887  [$80:8887]
$80/A1EA 20 0F A2    JSR $A20F  [$80:A20F]
$80/A1ED 20 E8 84    JSR $84E8  [$80:84E8]
$80/A1F0 AD 86 10    LDA $1086  [$80:1086]
$80/A1F3 29 FF 00    AND #$00FF
$80/A1F6 CD 82 10    CMP $1082  [$80:1082]
$80/A1F9 D0 02       BNE $02    [$A1FD]
$80/A1FB 80 F0       BRA $F0    [$A1ED]
$80/A1FD 9C 7A 10    STZ $107A  [$80:107A]
$80/A200 20 57 A3    JSR $A357  [$80:A357]
$80/A203 4C EA A1    JMP $A1EA  [$80:A1EA]

$80/A206 9C 7A 10    STZ $107A  [$80:107A] //the start of the programming that leads to the stage select and sound test menu, but no programming found that jumps here
$80/A209 20 57 A3    JSR $A357  [$80:A357]
$80/A20C 4C E4 A1    JMP $A1E4  [$80:A1E4]

Stage Values

Hex, decimal, description

0x43, 67 - Continue screen

0x45, 69 - Password entry
0x46, 70 - Title screen

0x50, 80 - New game

RAM addresses

7E1082 - copy of current stage (apparently, the game compares this against 7E1086 and if they're different, it triggers the stage change routine)
7E1086 - current stage

Misc.

$80/A8F1 A9 13 00    LDA #$0013              //change 13 to another value e.g., Pro Action Replay code 80A8F2xx, to have Gon perform different actions when pressing B to jump
$80/A8F4 4C 39 FA    JMP $FA39  [$80:FA39]

• Misc. load and play sound effect when Gon performs actions:

$80/AE21 A9 19 00    LDA #$0019              //sound effect index 19
$80/AE24 20 78 A3    JSR $A378  [$80:A378]

$80/AE2F A9 1B 00    LDA #$001B              //sound effect index 1B
$80/AE32 20 78 A3    JSR $A378  [$80:A378]

• Elephant sound effect $59 at start of second stage cutscene:

$80/93E3 B9 02 00    LDA $0002,y[$83:C0DB]
$80/93E6 22 72 9C 81 JSL $819C72[$81:9C72]   A:1959

Passwords

ROM addr., data
018DE9 A284 12 FFFF 1F8E //invalid password, can't be entered, returns to title screen
018DF0 A284 12 1104 298E
018DF7 A284 12 1212 328E
018DFE A284 12 1351 3B8E
018E05 A284 12 6419 448E
018E0C A284 12 8543 4D8E
018E13 A284 12 9625 568E
               ^^^^ password in decimal, reverse the bytes, e.g., 1104 is password 0411 for the second stage
                    ^^^^ pointer to password effects, below

018E29 0C5F 8E22 8610 5200 0D
018E32 0C5F 8E22 8610 5500 0D
018E3B 0C5F 8E22 8610 1E00 0D
018E44 0C5F 8E22 8610 5A00 0D
018E4D 0C5F 8E22 8610 5D00 0D
018E56 0C5F 8E22 8610 5F00 0D
                 ^^^^ RAM address 7E1086
                      ^^^^ STAGE index