PowerPak

The PowerPak is a flash cartridge made by RetroUSB. It uses an FPGA to emulate a wide variety of mappers, allowing the user to store a large collection of NES ROMs on a single Compact Flash card and run them on an NES. It is widely used by NES software developers to test their homebrew software.

Product page: http://www.retrousb.com/product_info.php?products_id=34

Mapper Compatibility

The PowerPak mappers have undergone several revisions, gradually improving compatibility. After official development ceased in 2010, Loopy and TheFox have each created a supplemental set of PowerPak mappers to improve its capabilities.

Power Mappers

TheFox created a set of revised PowerPak mappers to supplement or augment the existing ones, most notably adding a savestate feature.

Download: http://kkfos.aspekt.fi/projects/nes/powerpak/powermappers/

• NROM (0)
• AxROM (7)
• BxROM (34)
• CxROM (3)
• GxROM (66)
• UxROM (2)
• MMC1 (1)
• MMC2 (9)
• MMC3 (4)
• MMC3/TxSROM (118)
• MMC3/TQROM (119)
• MMC4 (10)
• FME-7 (69, no sound)
• Codemasters (71)
• ColorDreams (11)

Known problems:

• MMC3 IRQ can cause shaky status bars and similar problems on some systems.

Loopy's Mappers

Loopy released a set of revised PowerPak mappers in 2011, adding fixes and additional support for a several mappers:

Download: https://home.comcast.net/~olimar/NES/powerpak_loopy.zip

• CNROM (3)
• MMC3 (4)
• FDS
• NSF
• VRC4 (21, 23, 25)
• VRC6 (24, 26)
• N163 (19)
• Sunsoft-5B (69)
• BxROM (34)
• Codemasters (71)
• JY Company (90, partial)
• MMC5 (5, no sound)

Offical Mappers V1.34

The last official release of mappers was in 2010. It supports a wide variety of popular mappers.

Download: http://www.retrousb.com/product_info.php?products_id=34

TODO: list of supported mappers.

Known problems:

• MMC3 support is insufficient for Low G Man, as the mapper 4 implementation is Startropics-compatible instead of MMC3 accurate. See mapper 4 and MMC6.

Development limitations

Aside from mapper incompatibility, there are minor differences between running NES programs on the PowerPak versus a traditional single-game cartridge.

• The PowerPak does not accurately simulate power-on state. Because power-on always boots the PowerPak menu, RAM and various registers will be initialized to a consistent state before any NES ROM is chosen to run. (Reset state, howevere, is not affected by this problem.)
• Open bus behavior may be different in several memory regions that are used by the PowerPak, but would not be connected on a regular cartridge.