SidecarTridge Multi-device Oric Computer Emulator

Source code CHANGELOG Report BUG v1.0.1beta

This microfirmware app for the SidecarTridge Multi-device platform emulates an Oric computer in the Atari ST class of machines.

This emulator is based on the Reload Emulator project by Veselin Sladkov. Huge thanks for his great work!

Table of contents
  1. ⚠️ Attention
  2. 🚀 Installation
  3. 🕹️ Usage
    1. Configuration
    2. Emulator Controls
    3. ⏏️ Exiting to Booster
    4. 🔄 Power Cycling
  4. 🛠️ Under the hood
  5. What’s next
    1. Missing features, future roadmap
  6. License
  7. 🤝 Contributing

⚠️ Attention

This emulator is designed only for low-resolution monitors. It will not work in high-resolution modes.

🚀 Installation

To install the Emulator app on your SidecarTridge Multi-device:

  1. Launch the Booster App on your SidecarTridge.
  2. Open the Booster web interface in your browser.
  3. Go to the Apps tab and select Oric Emulator from the list.
  4. Click Download to install the app to your SidecarTridge’s microSD card.
  5. Once installed, select the app and click Launch.

After installation, the Oric Emulator will start automatically every time your Atari is powered on.

🕹️ Usage

Configuration

The emulator requires an image file with the Oric ROM to function. There are plenty of Oric ROM images available online, try searching for “orica.zip” or similar. Once you have the ROM image, rename it to rom.img and copy it to the directory /oric on the SidecarTridge microSD card.

This should be enough to get started, but if you want to load applications and games, copy .TAP or .WAV files to the same /oric directory with the following structure:

  • f1.tap or f1.wav - second tape file, loaded when pressing the F1 key.
  • f2.tap or f2.wav - third tape file, loaded when pressing the F2 key.
  • and so on…

Once the files are in place, launch the Oric Emulator app from the Booster interface or by rebooting your Atari with the Multi-device set to auto-launch the app.

Emulator Controls

The emulator currently only supports file loading from tape or wave images. Use the following keys to load the corresponding tape files:

  • F1 → Load f1.tap or f1.wav in the virtual cassette drive.
  • F2 → Load f2.tap or f2.wav in the virtual cassette drive.
  • F3 → Load f3.tap or f3.wav in the virtual cassette drive.
  • and so on…

If the file is of TAP format, it will convert it to WAV format and will save a copy as fX.wav in the same directory for future use.

After loading the tape file, use the command CLOAD"" in the Oric BASIC prompt to load the program from the virtual tape.

You can find plenty of Oric software online in places like Oric.org.

The HELP button will perform a soft reset of the Oric machine. The UNDO button will pause the emulation.

⏏️ Exiting to Booster

The emulator cannot exit back to GEM or the Booster interface directly. To exit the emulator and return to the Booster app, you need to power cycle your Atari ST and at the same time hold down the SELECT button on the SidecarTridge. This will interrupt the normal boot process and launch the Booster app instead of the Oric Emulator.

🔄 Power Cycling

After a power cycle, the emulator auto-launches.

🛠️ Under the hood

The Oric Emulator is built using the Reload Emulator core, adapted to run on the SidecarTridge Multi-device platform.

What’s next

Maintaining and improving this emulator is a hobby project for me. If you have any suggestions or find any issues, please feel free to open an issue on the GitHub repository.

Missing features, future roadmap

This is a solid first release and a fun experiment, but there is plenty of room to improve.

  • ✅ Better framebuffer (implemented since v1.0.1beta). It refreshes at 50 Hz, but shows the previous frame instead of the latest one.
  • Joystick/gamepad support.
  • Floppy disk support. I removed it to save CPU cycles, but that is not the right place to cut.
  • TAP file load menu. The function key solution is functional, but clunky.
  • Faster framebuffer build. Creating the Atari ST framebuffer from the Oric screen needs to be more efficient.
  • Performance improvements.
  • Direct TAP file load. The current code converts to WAV; it works, but is not ideal.

License

This project is released under the GNU General Public License v3.0. See the LICENSE file for details.

Note: the original Reload Emulator repository does not display a license, so I do not know what license to attribute for that upstream code.

🤝 Contributing

Made with ❤️ by SidecarTridge

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