Would it be feasible to design and build a Super Nintendo game cartridge board that hosts a Teensy and the hardware needed to interface with the SNES?

(Board mock-up I made in Blender 3d.)

My idea isnít to push game ROMs, that is what flash-carts or emulators are for. Instead I want to turn the SNES into a graphics and sound card for the Teensy so I can make games for the Teensy that use the SNES.

Iíd obviously have to learn SNES assembly programming and homebrew (https://en.wikibooks.org/wiki/Super_NES_Programming) but the idea in my head is to write an interface program for the SNES that the Teensy feeds it on power up. After itís loaded the Teensy can pull the interrupt line to send new data and instructions.

This site: https://www.caitsith2.com/snes/flash...p-pinouts.html has the cart pinouts. Looks like itís going to use up all the Teensyís pins or I could use a few shift registers to handle the parallel address and bank lines. Iíll also have to level shift the SNESís 5v to 3.3v so I can use a Teensy 3.6. The 8 bit data wires are bidirectional which might be tricky. Their direction would need to be determined by the state of /RD /WR lines.

As for the CIC Lockout chip. My current plain would be to copy the circuit layout and take the chip and cap from a spare game I have and put it on my board. Another option is to spoof the chip with a ATtiny. Google search shows itís been done, just need to track down code or a binary.

SNES hardware architecture: http://meseec.ce.rit.edu/551-projects/fall2014/3-1.pdf