Arcade-ChinaGate_MiSTer

FPGA core for China Gate (Technos Japan, 1988) targeting the MiSTer FPGA platform (Terasic DE10-Nano).

China Gate (Japanese title: Sai Yu Gou Ma Roku — Ryuu Bou You Gi no Shou, 西遊降魔録 流棒妖技ノ章) is a side-scrolling action / beat-em-up arcade game running on the same Technos hardware family as Double Dragon II: dual HD63C09 main + sub CPUs sharing RAM, a Z80 sound subsystem driving YM2151 FM synthesis and an OKI M6295 ADPCM sample player. The core reimplements the hardware in SystemVerilog from the MAME driver, the PCB schematics and pixel-accurate validation against MAME and original PCB footage.

Status

Current version: 1.0 (May 2026) — first public release.

The core runs the full game with audio and inputs.

Features

• HD63C09 main CPU @ 1.5 MHz (cycle-accurate core)
• HD63C09 sub CPU @ 1.5 MHz (sharing RAM with main via the Technos bus-arbiter pattern)
• Z80 sound CPU @ 3.579545 MHz
• YM2151 FM (jt51) + OKI M6295 ADPCM (jt6295) with MAME-accurate mixer
• 256×240 active video area
• FG text layer, BG tilemap with X/Y scroll, 16×16 sprites
• MiSTer OSD with audio mixer (FM/OKI volume + Pickup/Gong attenuators)
• Pause overlay with logo + supporters scroll

ROM sets supported

• China Gate (US) — reference set (chinagat)
• Sai Yu Gou Ma Roku (Japan) — original Japanese release (saiyugou)

Hardware emulated

Component	Spec
Master clock	12 MHz crystal (video) + 3.579545 MHz (sound)
Main CPU	HD63C09 @ 1.5 MHz
Sub CPU	HD63C09 @ 1.5 MHz (shared RAM with main)
Sound CPU	Z80 @ 3.579545 MHz
Sound chip 1	Yamaha YM2151 (jt51)
Sound chip 2	OKI M6295 (jt6295) ADPCM, pin7=HIGH, ~1.056 MHz
Video resolution	256×240 active
Refresh rate	~57 Hz
FG layer	4bpp text/HUD layer
BG layer	4bpp tilemap with X/Y scroll
Sprites	4bpp 16×16, with horizontal/vertical flip

Hardware requirements

• Terasic DE10-Nano
• MiSTer I/O board (recommended)
• Works on HDMI displays and on 15 kHz CRTs via the analog video output

Building from source

Requires Quartus Prime 17.0 (free Lite Edition).

Open ChinaGate.qpf in Quartus → Processing → Start Compilation

Output bitstream is generated in output_files/ChinaGate.rbf (~3.7 MB).

Running on MiSTer

The releases/ folder contains the parent MRA for the reference ROM set:

• China Gate (US).mra — parent MRA (reference set)

Alternative ROM sets are provided in releases/alternatives/:

• China Gate - Sai Yu Gou Ma Roku (JP).mra — Japanese release (saiyugou)

Following the MiSTer-devel convention, the alternative sets can be also mirrored to the official MRA-Alternatives_MiSTer repository, where they are picked up automatically by Update_All.

Steps:

1. Copy the .rbf to _Arcade/cores/ on the MiSTer SD card.
2. Copy the desired .mra file(s) to _Arcade/ on the MiSTer SD card.
3. Provide your legally-owned China Gate ROM files where each MRA expects them (usually in games/mame/).

ROMs are NOT included in this repository. You must provide them yourself.

Repository layout

Arcade-ChinaGate_MiSTer/
├── rtl/
│   ├── chinagate/    China Gate-specific core RTL
│   ├── pll/          Clock PLL
│   ├── sound/        Sound chip cores (jt12, jt51, jt5205, jt6295, t80)
│   └── sdram.sv      SDRAM controller (Sorgelig)
├── jtframe/          JTFRAME framework modules
├── sys/              MiSTer framework (Sorgelig / MiSTer-devel)
├── logo/             Pause overlay assets (font, logo, supporter list)
├── releases/         Parent MRA + alternatives
│   └── alternatives/ MRA files for alternate ROM sets
├── ChinaGate.qpf     Quartus project
├── ChinaGate.qsf     Quartus assignments
├── ChinaGate.sv      Top-level wrapper
├── Template.sdc      Timing constraints
├── files.qip         HDL file list
├── build_id.v        Build version stamp
└── README.md         This file

Acknowledgements

• Jose Tejada (@jotego) for JT51 (YM2151), JT6295 (OKI M6295), JT12, JT5205 and the JTFRAME framework.
• Greg Miller for the cycle-accurate MC6809 / HD63C09 core.
• Daniel Wallner and MikeJ for the T80 (Z80) core.
• Sorgelig and the MiSTer-devel team for the framework, SDRAM controller and Template.
• The MAME project for invaluable hardware reference (chinagat.cpp, ddragon.cpp, ddragon_v.cpp).

Support this project

If you enjoy this core and want to support its development:

• Ko-fi — one-time support
• Patreon — monthly support
• PayPal — one-time donation

Follow

• Twitch — live streams
• YouTube — playlists and videos

License

The RTL source code in this repository is provided as-is for educational and preservation purposes. Original ROM data is not included; users must provide their own legally obtained copies.

Original China Gate / 西遊降魔録 arcade hardware © Technos Japan Corp., 1988.