Sega Model 2 (Daytona USA) for MiSTer: work-in-progress beta.

This is Daytona USA running on a Sega Model 2 core for the MiSTer FPGA: the i960 main CPU, the TGP geometry coprocessor, a hardware 3D renderer, the 2D tilemap layers and the full sound board (68000, YM3438 and two MultiPCMs), all in the FPGA. What's new in this build 3D drawn into a DDR3 framebuffer. Each 3D frame is drawn off-screen and shown only when it's complete, so no torn frames or missing strips. Front-to-back rendering, as the real board does it. Polygons are drawn nearest first, and texture fetches are skipped for pixels already covered. That makes the 3D draw 15–36% faster. Road and scenery texture fixes. The bridge textures now load from the right place, the road pieces are in the right positions, and the twisted road corners are gone: those quads are now drawn as two triangles. Pixel-centre coverage, which removes the streaks and overlaps along polygon edges. 15 kHz interlaced video option (OSD → Video) for CRT users: 57.5 Hz fields of 192 lines. Not yet tested on a real CRT. Sound at the correct speed. It had been running about 40% fast. Cleaner OSD: developer options removed. Performance The game currently averages about 30 fps in attract (measured 30.7 fps over 60 seconds). The arcade runs at 57.5. The limit isn't the 3D drawing: turning textures off doesn't change the frame rate. It's the geometry stage, which is being worked on now, with speed-ups already in testing. Known issues Car windows sometimes lose their glass or reflection after a few minutes of attract. Occasional texture flicker on some trees and hills. Runs at about half the arcade's frame rate (see above). This is a beta and still changing daily. You'll need your own Daytona USA ROM set; no ROMs are included.