Results 1 to 2 of 2

Thread: Battle of Olympus Game Genie Codes Wanted

  1. #1
    Cherry (Level 1)
    Join Date
    Oct 2010
    Location
    Milwaukie (Oak Grove), Oregon
    Posts
    346
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Default Battle of Olympus Game Genie Codes Wanted

    Hi,

    Could anyone please help me as to what Game Genie codes will have one olive equate to eight olives? What would I change in the ROM so that collecting one olive yields eight?

    Game: The Battle of Olympus
    System: Nintendo Entertainment System (NTSC-USA)

    Thank you,



    Ben

  2. #2
    Cherry (Level 1)
    Join Date
    Jun 2003
    Location
    USA
    Posts
    361
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Default Battle of Olympus NES Game Genie olives

    Hmm, it doesn't look like there's a simple way to change from +1 to +8 olives within the 3 code limit the real Game Genie hardware allows. The problem is the the flag set when you're picking up an olive (memory address $006B set to #$01) is also the value placed in the accumulator to be added to the olive total. Unfortunately, the INC command was used instead of LOAD #$01.

    What CAN be done, however, is using Game Genie codes that trick the game into thinking that you're picking up the 100th olive, and it sets it back to the max of 99.

    Battle of Olympus NES (USA version)
    GGVISPAO + VAVIVPZP + OIVINPIV picking up one olive counts as 99

    For reference, here's the programming:

    $8E09:E6 6B INC $6B = #$01 //picked up an olive

    $D8A4:A5 6B LDA $6B = #$01
    $D8A6:F0 22 BEQ $D8CA
    $D8A8:20 60 D9 JSR $D960 //jsr add olive to total

    $D960:A4 E1 LDY $E1 = #$01
    $D962:C9 00 CMP #$00
    $D964:18 CLC
    $D965:10 12 BPL $D979
    $D967:65 E0 ADC $E0 = #$00
    $D969:10 1E BPL $D989
    $D96B:88 DEY
    $D96C:30 07 BMI $D975
    $D96E:18 CLC
    $D96F:69 0A ADC #$0A
    $D971:30 F8 BMI $D96B
    $D973:10 14 BPL $D989
    $D975:A9 00 LDA #$00
    $D977:F0 0F BEQ $D988
    $D979:65 E0 ADC $E0 = #$00
    $D97B:C9 0A CMP #$0A
    $D97D:90 0A BCC $D989
    $D97F:E9 0A SBC #$0A
    $D981:C8 INY
    $D982:C0 0A CPY #$0A
    $D984:90 F5 BCC $D97B
    $D986:A9 09 LDA #$09 //max 99 olives
    $D988:A8 TAY
    $D989:85 E0 STA $E0 = #$00 //olives ones place
    $D98B:84 E1 STY $E1 = #$01 //olives tens place
    $D98D:60 RTS

    The Game Genie set GGVISPAO + VAVIVPZP + OIVINPIV creates the following patch:
    $D965:4C 86 D9 JMP $D986

Similar Threads

  1. The Battle of Olympus (Game Boy)
    By ColecoFan1981 in forum Classic Gaming
    Replies: 3
    Last Post: 11-08-2013, 10:48 PM
  2. All SMS game genie codes in a zip file?
    By majinbuu in forum Classic Gaming
    Replies: 2
    Last Post: 08-19-2007, 09:50 PM
  3. Game Genie Codes for Megadrive?
    By Aeon010 in forum Classic Gaming
    Replies: 3
    Last Post: 08-08-2006, 06:01 PM
  4. good Game Genie codes (NES)
    By christhegamer in forum Classic Gaming
    Replies: 4
    Last Post: 12-31-2005, 09:59 PM
  5. I was creating game genie codes when my game genie died!
    By dragonlord in forum Classic Gaming
    Replies: 8
    Last Post: 10-31-2005, 11:10 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •