HuCard rom image downloading tips
You can download either TurboGrafx-16 games or PC-Engine games for play on your game system, but usually, the ROM file will have to be properly formatted before you can download it to the flash card. The main issue is that most of these roms will have "header files" included inside them, and these need to be removed.
Also, when using a USA rom with a JPN (PC-Engine) game system, there is a secondary form of region protection. This requires a data byte change, in order to remove region protection.
There is also a special formatting requirement (Rom mirroring) for games of 384K size.
To take care of all three of these rom formatting issues, there is a utility included in the Downloader software. By choosing File...Convert ROM, a window will open as shown below:
After you download a rom, open the *.pce file with the "ROM Conversion Tool" by pressing the "Select Rom" button. The software will evaluate the ROM and automatically check the necessary boxes. Press the Modify Rom button. Now your rom file is ready to download to the flash HuCard!
The Flash HuCard is physically wired for a USA system (Turbografx-16). If the game system that you will be playing the game(any region) on is Japanese (PC-Engine), then you will have to check the box on the Downloading Software, which swaps the bits of each data byte, before downloading the rom to the flash HuCard.