Coin-Op Collection Presents: T.M.N.T - Turtles In Time (Konami TMNT2)

In late March, I mentioned other major arcade platforms that were in development when releasing the first entry to our Cave 68000 implementation, and T.M.N.T: Turtles In Time is one of the platforms we've been working on!

None of this would have been possible without the reverse engineering work done by furrtek. An extensive amount of effort has gone into reverse engineering Konami customs, including the PCM (k053260), tilemap generator (k052109), and video mixer (k053251) components. The sprite generator (k053424/5) was reverse engineered in-house, and adjustments were made to the k053251 to support shadows and alpha blending.

There were several challenges to overcome; we'll have a technical entry for the platform in our Development-Documentation repository on GitHub in the future. This evening around 9:00 P.M. EST, Pramod will be covering some of the technical aspects on his Twitch channel for the release.

I've covered all of the K3 framework options previously, but I wanted to address stereo sound output and variant support. If an option isn't available, it's noted in the Known Issues section.

Core Options:

• Stereo Sound: If you'd like to experience stereo sound, go to the service menu, access game options and enable it. Afterwards, you can save this setting in the MiSTer OSD and toggle it on or off in the Audio Options.

  
  

• Variant Support: All known versions of T.M.N.T: Turtles In Time are supported. Some have specific cheats; if you are playing a two-player version, take note that player three and player four cheats do not apply. We've also bypassed the ROM/RAM checks with our own patch, so the post-check won't fail if you'd like to save settings or reset the core while cheats are active. By default, ROM Check is set to follow normal boot procedures.

There are some minor issues that still need to be addressed, and we're currently in the process of fixing a faulty component on the PCB that was used as a reference during development. Below is a list of known issues...

Known Issues:

• Attract Mode: The ring that zooms and scales has jitter; adjustment to the scalar formula is needed. This will be addressed once the PCB is repaired.

• Hurry Sprite: The largest sprite for Splinter has a double nose. This is related to the scalar issue above and will be addressed once the PCB is repaired.

• End Sequence: April O'Neil has a blue line due to zoom and scale offsets not lining up precisely in the scalar formula. This is related to the issue above and will be addressed once the PCB is repaired.

• Stage 4 Boss: Rahzar’s “puppy” sprite has a misplaced foot in the animation. This is the same issue as the "Hurry Sprite" and will be addressed once the PCB is repaired.

• Video timings for the front and back porch need to be captured with an oscilloscope, but this will have to wait until the faulty component is repaired. Until then, vertical positioning on CRTs will be limited, and the Refresh Rate toggle is currently disabled.

  
  

Our next release will address the known issues, hi-score saving, and a few additional features. We also plan to work on additional Konami games with similar hardware. While these titles may share common drivers, they are built on individual PCBs with shared components. We're aiming to target titles that use similar scaling techniques from 1992–1993 in the future.

We’ll share an update about Capcom CPS-III hardware with our next major platform release. That will either be a Sega or Taito core, whichever is finished first. I’ll post a development update here in the near future.

You can also grab this release from update_all — it’s available to the public. We hope all you dudes and dudettes have a Happy Easter and enjoy T.M.N.T: Turtles In Time with friends and family!

Update (2025/04/18):

• Hi-Score Saving: Support for hi-score saves has been added. Run update_all to grab the latest release.

• Cheats: Invincibility and One-Hit Kill ROM cheats work with all variants prior to MAME 0.271 release.

Update (2025/04/19):

• Reported Issue: Sound mix / NMI issue reported by a Discord user. FM audio was doubled (Donatello attack sounds / Rock Soldier attack sounds) due to FM audio being incorrectly assigned to the PCM audio path for NMI generation.

  • Fix: Corrected the ym2151 /k053260 assignments; aux1/aux2 and SH1/SH2 remain connected for NMI. Mixer adjusted to prevent the ym2151 from doubling FM audio.

• Configurable Player Assignments: Player 1's controller can now be reassigned. This feature swaps joystick and keyboard inputs according to your selected setting, allowing character selection flexibility. To change the assignment, go to Game Settings and choose your preferred option.

Disclaimer: 
All product names, trademarks, and registered trademarks mentioned are the property of their respective owners. "MAME", "MiSTer", "MiSTerFPGA", "Konami", "Capcom", "Cave" and all derivative works are trademarks, registered trademarks, or copyrighted materials of their respective holders. Use of these names does not imply endorsement or association with this post. All rights reserved to their respective owners. This post is for educational and research purposes only.