CHGameMiSTer

A MiSTer FPGA core for the CHGame handheld (WCH CH32X035 RISC-V chip, 128 x 128 ST7735 screen, piezo buzzer, microSD card). It reproduces the board cycle for cycle in the FPGA and plays CHGame .CHG games.

Status: public beta (v0.6). Every game tested runs at 100% speed on a DE10-Nano, over HDMI and on a 15 kHz analogue monitor. Expect rough edges; please report them.

The repository contains no games. Three free games by the core's author (CHix, STARLIFT and CHarth, MIT-licensed) come in the release zip's games/CHGame/ folder and through an optional downloader file; any other .CHG and .DAT files are your own.

Links: CHGame website · Arduboy forum (CHGame) · Buy a CHGame · CHGame API docs

The author's games

CHix	STARLIFT	CHarth

New public releases by the author are added to the optional games download automatically.

Install

With Downloader / update_all: follow docs/DOWNLOADER-USERS.md (add the two-line downloader_chgame.ini to the top of the SD card, then run update_all). Add downloader_chgame_games.ini too for the author's games.

By hand: copy CHGame_YYYYMMDD.rbf to _Console (or _Other) on the MiSTer's SD card, keeping only one CHGame .rbf there. Put your games in /media/fat/games/CHGame/. Details: INSTALL.md.

Playing

• Games: Load game in the OSD lists the .CHG files in games/CHGame.
• Data files: games that read the microSD card need their .DAT file: use Load data file (repeat for each file, up to 8; Clear data files forgets them). A card image can also be mounted.
• Saves: kept automatically as .sav files in saves/CHGame/ (Autosave or Save now). tools/savconv.py converts saves to and from the PC emulator's.

OSD pages:

• Main: load game / data file, mount image, speed (fast forward, speed display), autosave, pause when OSD is open, button mapping, and Fast card loading (Auto, Always on, Off): Auto speeds up a game while it loads from the card and returns to exact timing when it draws again.
• Video: analogue mode (15 kHz 1x, 1.75x, 240x240, 2x), V and H position, Per-game position (kept in each game's save), aspect ratio, scale, scandoubler effects, scale filter, LCD grid (2x only), LCD colours, LED dot.
• Audio: sound (bare pin or piezo models), volume, EQ preset, spectrum display.
• Equaliser: seven bands from 63 Hz to 6.3 kHz, used by the Custom preset.

15 kHz analogue output is 240p timing (15.625 kHz, 60 Hz) with the 128 x 128 picture square on a 4:3 tube; HDMI goes through MiSTer's scaler.

How it is checked

The Verilog in core/rtl is checked in Verilator against joyrider3774's C emulator (emu/), instruction by instruction and picture by picture (sim/, built with sim/vbuild.sh; set OSSCAD to the OSS CAD Suite folder, default $HOME/tools/oss-cad-suite). Those tests need your own .CHG and .DAT files, which are not included. The .rbf is built with Quartus 17.0.2 Lite from core/. Version history: CHANGELOG.md.

Credits

• The emulator in emu/ is joyrider3774's chgame_emulator (MIT).

• CHGame is by Kevin Bates (bateske/CHGame, Apache-2.0); its bootloader (MIT) is included as the factory flash image.

• The MiSTer framework (core/sys/) is MiSTer-devel's Template_MiSTer (GPL).

• CHix, STARLIFT and CHarth are by Jadflat (CHix, Starlift, CHarth), MIT; each uses Kevin Bates' CHGame library.

See NOTICE for the full list.

Licence

GPL-3.0-or-later; see LICENSE. Third-party parts keep their own licences, see NOTICE.