** SUMMARY ** BeagleSatella is a hardware/software solution that implements the basic interface functions of peripherals compatible with the Super Nintendo (SNES) and Super Famicom (SFC) game consoles. These consoles contain a rarely-used expansion port on their underside that was intended to interface with a variety of hardware peripherals. Unfortunately, very few commercial peripherals were made available, with the most widely used being the Japan-only Satellaview satellite modem.

BeagleSatella is not emulation, but an actual SNES add-on peripheral that plugs directly into your game console. BeagleSatella uses a BeagleBone Black (BBB)  single-board computer with a custom "cape" expansion PCB as the hardware to interface with the console. Firmware running on the BBB's pair of programmable real-time units (PRUs) provides the nanosecond-scale timing required to interface with the SNES in real-time. Additional peripheral behaviors are controlled using kernel drivers and userspace software running under the BBB's Linux OS.

** AUTHOR ** Andrew Henderson (hendersa@icculus.org): https://icculus.org/~hendersa

** DESCRIPTION ** The BeagleSatella hardware and firmware offers the following features:

• CPLD-based Hardware filtering and translation of memory-mapped I/O register accesses from the SNES B-Bus.

• Integrated JTAG interface for easy CPLD reprogramming.

• Arbitrary range of up to 64 contiguous memory-mapped I/O registers available.

• BBB PRU usage guarantees the servicing of register read/write requests within a 150 ns time window.

• Audio interfacing via the expansion port's stereo audio inputs.

** BUILDING ** Since BeagleSatella has both hardware and software aspects to it, this repository is broken down into several subdirectories:

• "cpld" contains the CUPL source code for the CPLD IC used on the cape PCB.

• "firmware" contains the PRU firmware for the BBB that communicates with the cape PCB.

• "images" contains schematics, board renders, and other images that provide a preview of the system.

• "kernel" contains the kernel driver and device tree files for the BBB so that the BBB can communicate with the cape PCB.

• "pcb" contains the KiCad design files and gerber files for the cape PCB.

• "userspace" contains BBB userspace software for high-level control of the whole BeagleSatella system.