Jump to content
NHL'94 Forums

How To: Enable 1 Minute Penalties [SNES]


McMarkis

Recommended Posts

Enable 1 Minute Penalties


Problem:
The SNES rom crashes when you try to modify penalties to be 1 minute, as the game developers never expected there to be 1 minute penalties.


Solution:
Modify the penalty length in the ROM and skip the problematic check for 0 or 1 if the penalty length is one minute.

Technical Details:

Similar to the "Defense Ctrl" code injection method, we have to swap out some of the existing code and insert a jump to new code that we create. This new code will be placed in the free space at the end of the 9E bank.

Problem Code:

image.png

Hijack Instruction before the problem code and run new code (One_Min_Pen)

image.png

Run new code to skip the compare if we know its a one minute penalty and continue like normal as if it was a 2 min penalty.

image.png

I have included the 1 min penalty rom to play around with or compare for differences if interested. Or you can download the tool and create your own ROM.

image.pngimage.png

https://github.com/Mhopkinsinc/NHL94SNESVault/releases

nhl94.sfc

Hex Version:

image.png

1) Change all the penalties from 02 minutes to 01 minutes.

Headerless ROM (.SFC)
ROM Offsets: (hex) 54C7,54E9,550B,552B,554B,556B,558C,55B1,55C9
Change:02 to 01

Headered ROM (.SMC)
ROM Offsets: (hex) 56C7,56E9,570B,572B,574B,576B,578C,57B1,57C9
Change:02 to 01

2) Hijack old code and point to the new code

Headerless ROM (.SFC)
ROM Offsets: (hex) F3417-F3419
Change:29 FF 00 to 4C 5B FB

Headered ROM (.SMC)
ROM Offsets: (hex) F3617-F3619
Change:29 FF 00 to 4C 5B FB

3) Insert new code that fixes the bug

Headerless ROM (.SFC)
ROM Offsets: (hex) F7B5B-F7B6D
Change: FF's to C9 01 04 F0 05 C9 01 0A D0 03 4C 21 B4 29 FF 00 4C 1A B4

Headered ROM (.SMC)
ROM Offsets: (hex) F7D5B-F7D6D
Change: FF's to C9 01 04 F0 05 C9 01 0A D0 03 4C 21 B4 29 FF 00 4C 1A B4

 

Edited by McMarkis
Updated, added Hex version so this can be done by hand
  • Love 1
  • Thanks 1
  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   0 Members, 0 Anonymous, 63 Guests (See full list)

    • There are no registered users currently online
×
×
  • Create New...