System information

Processor: 2A03 at 1.7897725MHz (NTSC) or 1.773447MHz (PAL), 6502-like instruction set (missing decimal mode), embedded audio generator (pAPU)
System RAM: 2KB
Graphics processor: Proprietary: picture processing unit (PPU) 2C02 - tile and sprite based display
Connectors (NES version): Cartridge slot, 2 controller ports, expansion connector, RF-out, AC power input, composite video output, mono sound output
Cartridge: Up to 32KB program + 8KB character ROM without mapper, unlimited with mapper. On-cart sound generation possible with famicom (not with NES!). Security IC to prevent unlicensed carts from being played. Cartridges may contain extra RAM which may be battery backed.
Sound: Mono sound with 2 square wave generators, 1 triangle wave generator, 1 pseudo white noise generator, DMC/PCM channel, cartridge sound feed (famicom only).
Power (NES): 9-12V DC/AC adaptor input. The NES is very tolerant over input power. The official PSU is 9V AC.
Input: 4-way digital d-pad with 4 action keys, light gun, keyboard... (quite a few)

Zipplet's Emulator