MAME 0.231, our April release, is out now! The Yamaha FM synthesis rewrite is progressing, with the OPL family (including YM2413, YM3526, YM3812, YMF262 and Y8950) done this month. A number of regressions reported against the previous release have also been fixed. Most things should be improved, but if you notice something wrong with a system using one of these chips, be sure to let us know. Warp-1, a very rare Sun Electronics game from the late ’70s, has been added this month. This is an early example of an “into the screen” space shooter.
For as long as it has been emulated, the “3D” stages in Contra have been too easy. This comes down to the functionality of the Konami 007452 chip, which Konami calls a VRC&DMP. Now we know that VRC stands for Virtual ROM Controller, and controls ROM banking. However, the DMP part has been more of a mystery, assumed to be some kind of protection. This month, furrtek worked out that it’s apparently some kind of Divide/Multiply Processor, for 16-bit maths operations that would be unacceptably slow on the games’s pair of 6809-family CPUs. The great news is the game now runs correctly, the bad news is you’ll probably die a lot more.
David “Haze” Haywood is back this month with fixes for several arcade games that have never been quite right. He’s fixed graphical priority issues in SNK’s Beast Busters and Mechanized Attack, improved timing in Seibu Kaihatsu’s Shot Rider, and corrected layer offsets in Mitchell’s Funky Jet. He also added support for a couple of protected Mega Drive bootleg games from Argentina. Recently, David has been streaming MAME gaming sessions, often highlighting under-appreciated games. You can watch the recorded streams on his YouTube channel. Still on the topic of things that have never been right, sasuke has been busy this month. He’s improved the Nichibutsu 1412M2 DAC playback rate and timer period calculation, most noticeable on the Mighty Guy soundtrack, and made Taito’s unicycling game Cycle Maabou playable.
That’s all we’ve got time for here, but you can read about all the additions, bug fixes, and enhancements in the whatsnew.txt file. As always, the source and 64-bit Windows binary packages are available from the download page.