I want to share a project I've been working on: Aura MSX, a fully working MSX1 emulator for the M5Stack Cardputer.

What is Aura MSX?

Aura is an MSX1 emulator written from scratch for the Cardputer. It runs real MSX software — games, BASIC programs, and tools — straight from the SD card, with a custom launcher to pick what to load.

Under the hood:

• CPU: Z80 core by superzazu
• Video: TMS9918A VDP emulation
• Sound: AY-3-8910 PSG
• BIOS: C-BIOS (free and open-source — no proprietary firmware required)
• Custom launcher to browse ROMs and cassette images from the SD card

Datasette module (this is my favorite part)

Aura includes a working Kansas City Standard datasette emulator. It outputs FSK audio at 1200 baud through the Cardputer's headphone jack, so you can:

• Save BASIC programs from the emulator as real .cas files
• Load .cas files placed in the /cintas folder on the SD card
• Connect the headphone output to a real MSX and transfer programs to original hardware

The timing was validated against cas2wav to make sure the audio is bit-accurate.

Hardware compatibility

Aura runs on both the original Cardputer and the Cardputer-ADV from a single binary. On the ADV, it uses the TCA8418 keyboard and the ES8311 audio codec automatically.

How to use it

1. Flash the firmware to your Cardputer
2. Prepare a FAT32 microSD card with:
   • ROM files in the root or in a folder
   • A /cintas folder for .cas cassette images
3. Insert the card, power on, and the launcher takes over

Documentation

A full Spanish user manual is included, plus a printable trifold quick reference card.

SD (FAT32)
/msx/roms/ cartuchos .ROM
/msx/disks/ programas .BAS
/cintas/ cintas .CAS

I'll be uploading it to M5Burner shortly so it's a single click to flash. I'll edit this post with the link once it's up.

Feedback, bug reports, and suggestions are very welcome.

Cheers,
Altaris Software