Mike Tyson's Punchout!! (PC-10) Freezes After Glass Joe Fight

[omn1slash]

I've attempted loading both an old ROM (header) and a NES 2.0 header of the game, while the game loads fine once you fight Glass Joe and it goes to show the leaderboards (this version of the game has them in between fights), the game soft locks and crashes. It seems to soft lock when It tries to show the leaderboard.
This is specifically tied to the Playchoice-10 version of Mike Tyson's Punchout!!! that includes the leaderboard save function and not the retail version.

Mike Tyson's Punch-Out!!.nes

[littlegamer87]

https://forums.nesdev.org/viewtopic.php?t=9392

Seems like normal behavior for the game to crash if there is no WRAM to write to. The MMC2 is unique to MTPO. I am guessing adding WRAM to the mapper should fix this, assuming it does not break the retail game. But that would probably also trigger saving routines in the retail version when there is nothing to save. Ideally a new mapper should be specified for this rom I suppose.