Nintendulator the Nes Emulator for Windowshas had a new beta release, Supported file formats include .NES, UNIF, FDS (fwNES format), and NSF. Mappers are handled using external DLLs, complete with extra sound channels for most games which provide them. Other notable features include writing to FDS images (by storing the differences in the SRAM folder), Game Genie support (limited to 3 codes), customizeable controllers (including 4 player), input movie recording and playback (with re-recording), AVI capturing, and a debugger.

More info --> http://www.qmtpro.com/~nes/nintendulator/

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