cardputer-atari800

Atari 8-bit (800XL / 65XE / 130XE / XEGS) emulator firmware for the M5Stack Cardputer-Adv.

Based on the upstream atari800 emulator core, ported to the ESP32-S3 running Arduino framework via PlatformIO.

Status

Current working reference firmware: v0.3-m3-t11a-renderperf.

• M1 - bootstrap + HAL smoke test
• M2 - atari800 core integration + first rendered frame
• M3 - keyboard/joystick routing, fast POKEY audio, usable ROM browser
• M4 - browser polish, full in-emulator menu, settings persistence
• M5 - save states + final polish

Implemented beyond the original M2 baseline: AltirraBASIC boot, SD ROM/ATR/XEX loading via Fn+L, fast ROM browser enumeration, Cardputer keyboard + joystick mapping, raw ES8311/I2S audio, Atari console/key-click sounds, and dirty-row LCD redraw optimization.

Build

Requires PlatformIO Core:

brew install platformio

Compile:

pio run -e cardputer-adv

The build produces .pio/build/cardputer-adv/firmware.bin.

Flash

The normal workflow keeps M5Launcher as the boot firmware and writes this app into Launcher's OTA app1 slot.

Direct app1 flash over USB download mode:

pio pkg exec -- esptool.py --chip esp32s3 --port /dev/cu.usbmodem101 \
  --baud 921600 write_flash 0x170000 .pio/build/cardputer-adv/firmware.bin

SD/Launcher workflow:

COPYFILE_DISABLE=1 cp .pio/build/cardputer-adv/firmware.bin \
  /Volumes/CARDPUTER/downloads/cardputer-atari800.bin
sync

Then on the Cardputer, select the bin from Launcher's SD browser.

Serial monitor

pio device monitor is unreliable with the Cardputer USB-CDC re-enumeration on macOS. Use the active /dev/cu.usbmodem* port directly:

stty -f /dev/cu.usbmodem101 115200 raw -clocal -echo
cat /dev/cu.usbmodem101

Host-side tests

Pure-C logic is covered by a CMake test harness:

cmake -B build -S test
cmake --build build
ctest --test-dir build --output-on-failure

The current baseline has 17 host tests.

License

GPLv2 (inherited from upstream atari800). AltirraOS / AltirraBASIC ROMs included under their respective redistributable terms.