Naomi support in libretro Reicast cores

The libretro team shared the news about an exciting new feature: Their Reicast cores, both Reicast and Reicast OIT, support now Sega Naomi arcade games.

What is Sega Naomi?

Naomi was an arcade videogame system based on the Sega Dreamcast hardware and the successor of the Sega Model 3. While being nearly identical in terms of architecture, it did have double the RAM and fillrate of the home console version.

Naomi became one of the longest lasting arcade systems to be used second only to the Neo Geo AES. Various licensees (such as Capcom, Arc Sys, and even Nintendo) licensed the hardware during its lifespan to produce arcade games with.

How to use it

You will need a NAOMI BIOS file inside your system directory. The BIOS with the best compatibility so far is epr-21576g.ic27. This is a file that is contained inside the MAME NAOMI bios zip. Rename this file to naomi_boot.bin and move it to your ‘system directory/dc directory.

Try to get the file epr-21576g.ic27.

What content to use

You will need roms that worked on nullDC Naomi. These will typically be .dat/.lst or .bin/.lst pairs.

The last value of the .lst file specifies the size of the .dat/.bin file in hexademical value.

Here is an example of the .lst file used for Toy Fighter –

Toy Fighter
“Toy Fighter.dat”, 0x0000000, 0x05800000

You can find the existing .lst files here.

NOTE: MAME ROMS won’t work (yet). Proper Atomiswave roms won’t work, however, most Atomiswave to Naomi GD-ROM conversions should at least work or boot.

Currently existing issues

There are some issues that remain with Naomi support:

  • By default, two arcade sticks are hooked up.
  • There are some video and syncing glitches right now. One of the most immediately apparent is the flickering Naomi boot screen.
  • There is no analog and/or shoulder button support yet for Naomi games.

Videos

Toy Fighter

Dolphin Blue

King of Fighters XI

Dead or Alive 2 Millennium

Street Fighter Zero 3 Upper

A new core option called ‘GD-ROM Fast Loading Mode’ has been added. It can severely cut down on loading times, sometimes even removing them almost entirely as can be seen in the game ‘Daytona USA 2001’ here.

Various sound fadeout bugfixes

Through some judiciously applied hacks, the following games no longer suffer from sound fadeout issues:

  • Border Down
  • Bomberman Online
  • Chaos Field
  • Death Crimson OX
  • Fatal Fury/Garou: Mark Of The Wolves
  • Jet Set Radio/Jet Grind Radio
  • Napple Tale
  • Phantasy Star Online
  • Phantasy Star Online Ver. 1
  • Radirgy
  • Segagaga
  • Sonic Shuffle
  • Trigger Heat Exelica
  • WWF Royal Rumble

Graphics fixes

Thanks to the awesome efforts of flyinghead, several graphics glitches have been fixed, like Virtua Tennis or Psyvariar 2.

Other changes

Reicast OIT

  • Added an accumulation Pixel Buffer Size core option. You can set this to 512MB, 1GB or 2GB, depending on how much VRAM your video card has. For higher resolutions to output correctly, you might need to increase this to the highest value possible.
  • House Of The Dead 2 failed a verify assert – should boot and be playable now.
  • Rebase ADPCM decoding.

Reicast (non-OIT)

  • Multipass rendering is now enabled by default. Plenty of games need this for accurate rendering and the performance tradeoff should be minimal.
  • House Of The Dead 2 failed a verify assert – should boot and be playable now.
  • Rebase ADPCM decoding.

Source: https://www.libretro.com/index.php/reicast-libretro-now-supports-naomi-other-additions/

 

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.