popular video games

Loading a Game Doctor Game

To operate a Game Doctor, first connect the Game Doctor into the Famicom’s cartridge slot. Next, connect the RAM Adapter to the top of GD, the RAM Adapter cable into the back of the FDS, and connect a power supply to the GD, Famicom, and FDS. When you turn on the Famicom you will see the normal FDS disk prompt. To “activate” the Game Doctor, you must insert a disk in a particular format which contains a hacked “ROM”, only then will you see something outside of the normal FDS loading screen. If the GD game you load is multiple sided (game is over 64k), you will be prompted to insert the next side once a side has finished loading into the Game Doctor’s memory. This is the only user interface that you will see.

The video below shows what you’ll see on the TV as you load a GD formatted game with your Famicom Disk System and GD. The on-screen prompts tell you when to load the next disk side or if an error has occurred while loading a disk. Once all disk sides have been loaded, the game will start without showing the Nintendo Copyright screen. The game in this video is 2 full disks, sides A through D, and is called D.J. Boy, a title hack of Rollergames for the NES.

Famicom Game Doctor Formats

Famicom Disk System copiers have only 2 components:

1. the BIOS which intercepts FDS data flow and reroutes it to Game Doctor memory and starts the game; and
2. the hardware which is basically ONE multiple-state mapper which can play (C)NROM, U(N/O)ROM GNROM and two custom “mappers”

GD disk formats include the base GD format. It also includes upgrades by FFE and Venus, which are upwardly compatible with later units:

• GD 1M/2M format (supported by ALL units)
• GD 2M hacked images (supported by some GD2M, mostly compatible with GD4M, GM, TGD4, TGD6)
• GD 4M hacked images (supported by GD4M, mostly compatible with GM, TGD4, TGD6)
• Magic Card 2M hacked images (supported by MC2M, MC4M)
• Magic Card 4M hacked images (supported by MC4M) – few hacks exist
• Turbo GD 4+ hacked images (supported by TGD4) – few hacks exist
• Turbo GD 6+ hacked images (supported by TGD6)

The only disks that are NOT compatible with other copier units are Front FarEast (FFE) format Magic Card disks. However, some Magic Card disks will work in GD because they’re in the basic GD format, while others won’t because they’re protected. Most hacked Game Doctor games won’t work in Magic Card copiers because the BIOS actively rejects them, displaying an error message, such as “CAN’T USE!!” The games that will work are usually SNROM hacks (a MMC1 configuration) because the games fit well into UOROM, a discrete mapper playable on any copier.

The different types of game doctor/copiers are:

• MagiCard II Turbo
• Venus Game Converter
• Bung GD2M
• Bung Super GD4M
• Venus Turbo GD4+
• Venus Turbo Game Doctor 6+/M
• Bung Multi GD 1 – 4M/8M
• Venus Game Saver

About the Author

Famicom Disk System is an information repository for documentation and tutorials about how to write, copy and dump your Famicom disks using various methods as well as Famicom copiers, disks, and system modifications.