I came across Messiaen64's Hex editing method for inserting GameShark codes into a ROM, and thought "I bet I could turn this into a C program". So here it is:
This is a Windows program (Windows 95-Windows 10 32/64-bit are supported) that can write some GameShark codes either read from a txt file or typed by the user to the ROM. After you run the program on your ROM simply Chksum64 it and test it out.
Here's a WIP list of known supported codes:
SM64GSW is open source under the 3-clause BSD license.
Feedback & Discussion on this is highly appreciated!