SnesEmulator

A working Super-Nintendo emulator.

Purpose

This is intended as a showcase of my abilities as a C++ programmer. The source code is, in design and implementation, all my own creation.

Scope

This emulator will probably never be able to run all or even most SNES games, let alone have all the features of some of the other emulators out there. I will be extremely pleased if some day I manage to finish my three favorite SNES games on it, namely

• Super Mario World
• The Legend of Zelda - A Link to the Past
• Super Metroid

As of now, these three games are playable, though the audio is limited in features.

Build dependencies

In order to build the source you will need a compiler capable of C++20. Visual Studio 2022 Community is the main tool I use, but I have also worked to keep compability with GCC (v7.3.1) and CMake (v3.10). You will also need

• OpenGL (v3.2)
• GLFW (v3.4)
• PortAudio (v19.7)

Sources and acknowledgements

I read a lot to get started with this project. So far I have found that the following documents contain all the information on the SNES I needed to write this emulator. Most of them are a product of the work of other enthusiasts who often had to reverse engineer the hardware themselves. Without them, this would have been a much harder task.

WDC 65816 (CPU)

Table of opcodes

http://www.defence-force.org/computing/oric/coding/annexe_2/index.htm

Description of opcodes

http://www.6502.org/tutorials/65c816opcodes.html

Data sheet

http://www.westerndesigncenter.com/wdc/documentation/w65c816s.pdf

Decimal mode

http://www.6502.org/tutorials/decimal_mode.html

SPC-700 (Sound processor)

Table of opcodes, register descriptions, and boot ROM

https://github.com/naffnuff/SnesEmulator/blob/master/doc/Anomie's%20SPC700%20Doc

DSP (Digital Signal Processor, part of the sound processor)

General

https://github.com/naffnuff/SnesEmulator/blob/master/doc/Anomie's%20S-DSP%20Doc

BRR (Bit-Rate Reduction)

https://wiki.superfamicom.org/bit-rate-reduction-(brr)

SNES

registers

https://github.com/naffnuff/SnesEmulator/blob/master/doc/Anomie's%20Register%20Doc

memory map

http://simsnex.tripod.com/SNESMem.txt

timing

https://github.com/naffnuff/SnesEmulator/blob/master/doc/Anomie's%20SNES%20Timing%20Doc

transparency

http://folk.uio.no/sigurdkn/snes/transparency.txt

I did not in any way reverse engineer the SNES myself. In addition to relying on said documents I spent some time stepping through the debuggers of two emulators, Bsnes Plus (v05.35) and SnesX9 (v1.51.ep10r2 with Geiger's debugger), comparing their emulation state with mine and analyzing the behaviours I had an extra hard time understanding. The former is known for it's fidelity to the SNES hardware and has a very user-friendly debugger, whereas the latter was mainly useful to me for analyzing (H)DMA.