Add Wonderswan and NeoGeo Pocket emulators

[geo-tp]

I recently worked on a similar project called Game Station (for the ESP32 Cardputer), which was directly inspired by retro-go. The Cardputer is based on an ESP32-S3 without PSRAM

I ported two additional emulator cores:

• WonderSwan / WonderSwan Color

• Neo Geo Pocket / Neo Geo Pocket Color

I thought they could also be nice additions to retro-go, both cores run using less than 256 KB of RAM.

https://github.com/geo-tp/Cardputer-Game-Station-Emulators/

You can see here in the video, the NGP core running

https://www.reddit.com/r/CardPuter/comments/1pmkvyt/cardputer_game_station_09_added_snes_emulator_i2c/

[ducalex]

Impressive work, thank you for sharing!

I'm very interested in adding your NGPC and WSC emulators to retro-go. Right now I'm still catching up on the many issues/prs/emails from the past couple months but I'll definitely look into adopting your two ports. I presume that you have to copy the ROM to flash to make it all work without PSRAM but I'm intrigued if you've done further improvements to reduce memory usage :).

[geo-tp]

Regarding the ROM, it is indeed mapped to flash rather than PSRAM. The cardputer's ESP32S3 has 8MB of flash memory, 2MB are used for the emulator cores, and the remaining 6MB are for mapping the ROM at runtime from the SD card.

Concerning improvements, for console like genesis/snes, the cores were massively modified to work without a framebuffer and save as much RAM as possible to fit within the cardputer's 320KB of RAM. Otherwise, for system like gb/pce/lynx/sms/nes, I just made some changes to global array declarations/struct, changing them to pointers that initialize at emulator startup to increase the available RAM

I can help with the ngp/ws core integration if needed, when you have the time