cxNES is an open source, cross-platform NES/Famicom emulator. It is mainly written as a part-time hobby project to suit the needs of its author, but with accuracy, performance and portability as primary goals.

cxNES is written in C and uses SDL 2.0 for graphics, sound and input, and GTK+ for the GUI toolkit. It should have the same functionality and roughly the same look and feel on all supported platforms. Currently only Windows and Linux are supported; OS X support will be coming as soon as the author can get a Mac for development and testing. Other unix variants may work as well provided they have working SDL 2.0 and GTK+ libraries, but none have been tested.

You can contact the author at perilsensitive@gmail.com.

Features

Supported Image/ROM Formats

• iNES/NES 2.0
• UNIF
• Split ROMs (zipped, must be recognized by database)
• FDS
  • fwNES (.fds) format, with or without header
  • “Raw” format (includes gaps, start marks and checksums)
• NSF

Input Devices/Accessories

• Standard Controllers (NES and SNES)
• Four-player adapters (NES and Famicom types)
• Arkanoid Controllers (NES and Famicom variants)
• Zapper
• Power Pad
• Family Trainer
• Family BASIC Keyboard
• SUBOR Keyboard
• SNES Mouse
• VS. Unisystem support

Supported Expansion Audio Chips

• Nintendo MMC5
• Konami VRC6
• Konami VRC7
• Sunsoft 5B
• Namco 163
• Famicom Disk System

iNES Mapper Support

• 0, 1, 2, 3, 4, 5, 7, 9, 10, 11, 13, 14
• 15, 16, 18, 19, 21, 22, 23, 24, 25, 26, 28, 29
• 30, 31, 32, 33, 34, 36, 37, 38, 39, 41, 44, 46
• 47, 48, 49, 58, 60, 61, 62, 64, 65, 66, 67, 68
• 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 82
• 85, 86, 87, 88, 89, 90, 91, 93, 94, 95, 97, 99
• 105, 107, 112, 113, 115, 118, 119, 133, 137, 138, 139, 140
• 141, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153
• 154, 155, 158, 159, 166, 167, 178, 180, 182, 184, 185, 189,
• 192, 193, 200, 201, 202, 203, 205, 206, 207, 209, 210, 211,
• 218, 225, 226, 228, 230, 231, 232, 234, 240, 241, 245, 246

Patching

• Supports IPS, UPS and BPS patch formats
• Autopatching support
• Soft-patching
• Patches may be applied via GUI or specified on the command line
• Patches may be included in ZIP files with ROMs or disk images

Video

• Bisquit’s NTSC palette generator
• Blargg’s nes_ntsc filter
• User can specify a 64 or 512 color external palette file to be used instead of the generated palette.
• Enhanced sprite limit workaround: limits sprites for scanlines where the limit appears to be exploited intentionally, otherwise does not limit sprites.
• Supports correct TV aspect ratios for NTSC and PAL consoles
• PNG screenshots

Input

• Flexible input binding support
  • Nearly all emulator actions can have custom keyboard and/or joystick mappings
  • User-defined ‘modifiers’ useful for button combos on gamepads with few buttons (such as standard NES controllers)
• SDL GameController API
  • Allows supported joysticks (including XInput devices) to have a common set of sane default mappings.
  • Additional gamepads may be added by editing a plain-text mapping database
  • SDL Joystick API also supported for devices not recognized by the GameController API.
• Turbo support for controllers
  • Supports dedicated turbo buttons
  • Supports toggle buttons to enable/disable turbo on the standard A and B buttons.

Misc

• Savestates
  • Can auto-load/save states on ROM load/unload
  • Can auto-save state at a user-specified interval
• Dynamic audio resampling
  • Uses Blargg’s blip_buf resampler
• Cheat support (Game Genie, Pro Action Rocky, and raw formats)
  • Cheats can be auto-loaded/saved on ROM load/unload
• ROM Database (optional) for handling ROMs with incorrect or missing headers.
• Can be compiled or run without the GUI
• Can specify configuration options, patches and cheats on command line
• FDS enhancements
  • High-level optimizations of FDS disk I/O routines (optional)
  • Automatic disk selection and change for most FDS games (optional)
  • Writes to FDS images saved as IPS patches
• Windows builds can be configured to run in portable mode, storing all user data (save files, states, etc.) in the application directory.