https://www.youtube.com/watch?v=WZmMP82XPoI
This project contains the source material for the Arcade Classic 2, a hybrid hardware/software YM2151 video game music (VGM) player. This device is based off of the Mega Blaster 2 platform which was designed to play Sega Genesis/Megadrive VGM files. This project utilizes a hybrid approach for rendering audio. All FM portions of the VGM file are played through a genuine YM2151 sound chip, while any extra soundchips, namely PCM soundchips, are pre-rendered and fed into an audio mixer circuit. While it would be awesome to have genuine hardware support for every chip that was ever paired up with the YM2151, there are several factors that make that approach completely unfeasible. Namely, the vast amount of hardware configurations, memory requirements, sheer board space required, and rarity of components. Therefore, this player is essentially playing back a WAV file for the external chips while also driving the genuine FM sound generator and mixing them together. The result sounds pretty awesome!
The Arcade Classic 2 will read standard VGM/VGZ files just fine, however, in order to enable pre-rendered PCM support, you will need to quickly run your VGM files through a tool I've created. This tool will render out any portions of the VGM file that aren't controlling the YM2151 into a WAV file. The tool will then append the WAV data to the original VGM file. Finally, the tool will change the VGM header information so that the Arcade Classic 2 will recognize it as a PCM-compatible VGM file.
This tool is only compatible with Windows systems for now. It's fairly simple to use:
Download the VGM_To_VGP Tool Here!!!
- Drag-and-drop VGM/VGZ files or folders containing VGM/VGZ onto the executable
- Let the program render out each track
- Add the newly created "VGP" files to your SD card!
Please note: WAV data is very bulky and will take up significantly more space than simple VGM/VGZ files. This tool was written in C++ with Visual Studio 2017. It invokes VGMPlay to render the soundchip WAV data, then invokes SoX to ensure that the WAV data is in the correct format. The source code for VGM_To_VGP can be found here
VGM files are logged datasets of the data that would have been sent to the real sound chips of whatever console or arcade machine was being sampled. The Arcade Classic 2 simply reads-in this data and sends it to the sound chips at the exact rate specified in the VGM spec, accurately recreating the original sound.
You can find lots of VGM files here for all sorts of systems: https://vgmrips.net/packs/ The Arcade Classic 2 is only designed for soundtracks featuring the YM2151 sound chip. Technically, you could pre-render any VGM track you wanted and play it just fine, but that would essentially just be a WAV player with extra steps.
Please make sure to remove any non-vgm/vgz files before adding them to your Arcade Classic 2's SD card, such as album art images, playlist files, and text files.
VGZ files are gzip compressed versions of VGM files. The Arcade Classic 2 is capable of automatically decompressing these vgz files on-the-fly at a slight performance penalty. If you'd like faster load times for each track, consider decompressing the VGZ files in advance by opening them with a program like 7zip The Arcade Classic 2 does not require file extensions in order to operate as it will verify files based on their internal headers.
Here are some quick tips for building your own board.
- You can find an interactive Bill of Materials (BOM) within the
schematic->bomfolder. Open the HTML file in any browser for an easy-to-use part position guide. - I use KiCAD as my EDA suite.
- I buy most of my components from LCSC. I buy my PCBs from JLCPCB. If you buy your PCBs from JLCPCB, you can often get a shipping discount on your LCSC parts order.
- You will need an Atmel ICE or Jlink to flash the bootloader. Once you have flashed the bootloader, all subsequent programming can be done via the on-board USB port. A cheaper option would be to grab a Jlink EDU Mini as they feature the full functionality of a professional Jlink Unit with the stipulation that it is ONLY to be used for educational purposes. I personally use an Atmel ICE unit. You can find the bootloader bin file in the
bootloaderfolder of the repository. You can find an example of me programming the bootloader using Microchip Studio here. This is the same bootloader that the Mega Blaster 2 uses, so the process is the same. You may notice that your Arcade Classic 2 is identified by your computer as a "Mega Blaster 2." This is fine. - Once you've flashed the bootloader, you can drag the .uf2 firmware file found on the releases page on to the "drive" that pops up on your computer, or build from source. If you can't see any "drive," make sure the bootloader mentioned above is flashed correctly, then try double-tapping the RESET button.
- If your OS reports a USB fault, you may have a short somewhere on your USB IO lines, power lines, or your 32.768KHz crystal is not hooked up correctly.
- If you'd like to modify the firmware, I use Visual Studio Code with the PlatformIO extension.
As you can imagine, this is quite a complex project. There are bound to be bugs to squish, so if you happen to find any, please report them over on the issues page so I can tkae a look at them! Please try to document the steps it takes to recreate the bug if you happen to know them.
The source code to this project is licensed under the AGPL 3.0 license.
The printed circuit board design files for the Arcade Classic 2, including it’s schematic, gerber files, KiCAD files, bill-of-materials, and 3D models are licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 license.
You are permitted to build your own Arcade Classic 2 units for personal use. You are not permitted to sell said units.