NES Technical Documents

General information about the Nintendo Entertainment System, or Famicom
Name Author Download Summary
General Mapper Docs \Firebug\ ZIP General info on the NES mappers and how to emulate them.
Mapper #1 Docs Matt Richey ZIP Information on the NES mapper #1
Mapper #6 Docs FanWen Yang ZIP Information on the NES mapper #6
NES System Arthiceture Node99 ZIP Detailed information on the NES system arthiceture and the opcodes it uses. Invaluable to emulator authors.
Famicom Format Zofo ZIP Famicom Format Information.
MMC Schimatics Y0SHi ZIP Nintendo's schematics of the MMCs.
Y0SHi's NES Documentation Y0SHi ZIP It is another one of Y0SHi's excellent NES documents. I recommend you use them.
NES Programming Guide Bokudono and Waseiyakusha ZIP Explains the basics of NES programming
The Skinny on NES Scrolling loopy ZIP Information on background scrolling
The NES Sound Channel Guide Brad Taylor ZIP This document should help you better understand NES sound channel's.
How NES Graphics Work Unknown ZIP A document describing the basics on how NES Graphics Work.

Information about the 6502. The NES's 2A03 CPU is a modified 6502
Name Author Download Summary
6502 Microprocessor info Unknown ZIP Excerpt from the Commodore 64 Programmers Reference Manual.
Assembly in One Step Unknown ZIP A brief guide to programming the 6502 in assembly language.
6502 Instruction Summary CricketNE ZIP A list of opcodes and addressing modes.
6502 bugs Ivo van Poorten ZIP A list of known bugs in the 6502
Undocumented Opcodes Freddy Offenga ZIP Don't really guys tell me

Information about the NES/Famicom's add-ons, or anything that doesn't pertain to another category
Name Author Download Summary
NES Audio Ripping Chris Covell ZIP Everything you should need to know when ripping NES audio if you should want to include it in your emulator.
Game Genie Code Format Benzene ZIP Some information on the Game Genie code format.
4 Player Adaptor Fredrik Olsson ZIP 4 player adapter spec sheet.
NES Controller Schematics Tennessee Carmel-Veilleux ZIP This is info needed to make an adapter to plug an NES controller into.
Excite Boxing goroh ZIP General mapper information for this addon.
Family Computer Gun goroh ZIP General mapper information for this addon.

Information related to the emulation of the NES/Famicom
Name Author Download Summary
NES Header VmprHntrD ZIP iNES Header Format Information.
NES Palette Generator Kevin Horton ZIP Source code with an intro about this palette generator.
NES Palette Matt Conte ZIP Another palette document.
NES Palette Loopy ZIP Yet another palette document.
.STA Format Goroh ZIP NESticle .43 save state format info.