nesdev.org

The cheat module and associated $200B snescmd_buf handle some features for the menu like fades and reset related things. The firmware fully unlocks the $2A00-$2BFF block for the menu and then it gets locked (open bus to SNES) except for certain events like NMI/IRQ hook execution. The hook code attem...

I recall seeing something about loading the firmware over JTAG using USB when reading through the source. Maybe that's how it was done before the bootloader supported it from the SD card. There is a custom firmware that enables the USB port and adds some features: http://forums.nesdev.com/viewtopic....

There's a 14-pin bus on the side of the sd2snes (next to the battery). 3 of those pins are the UART output where the firmware printf output goes to. You can solder in a header and get a 3-wire UART to USB cable to view the output in a serial terminal. 3-GND, 6-RX, 7-TX. Hopefully the attached pictur...

The 16 MB RAM that's hooked up to the FPGA has enough bandwidth to write 2B between SNES bus operations which works out nicely for the 2B PPU registers and all other state. By itself, the context engine fits in the FPGA without removing the special chips, but I also added a RAM DMA engine to speed u...

A few years back one of the other forum members here enabled use of the USB connector on the SD2SNES. Those changes were used as a base for a small project to view and modify SNES state over USB. The version linked below has: - A basic protocol over USB that supports reset, booting of games, SD card...

I have a modified version of the sd2snes FW that allows file upload/download over USB along with some other functions. It also has some changes for real-time IPS patching of a running game. As a test of the IPS patching feature I pieced together some save-state code that uses FW changes to support r...