By default, DOSBox-X starts the standard IBM-compatible DOS system, not the PC-98 system. But you can specify a different system to start with the "machine" option in DOSBox-X’s configuration file (dosbox-x.conf by default), which offers system types including PC-98. So if you set "machine" to "pc98" (or "pc9801"/"pc9821" which are synonyms for "pc98" at this time), then DOSBox-X will start in the PC-98 emulation mode.

Alternative you can specify the PC-98 machine type directly at the command line when starting DOSBox-X, such as dosbox-x -set machine=pc98, which will immediately start DOSBox-X in the PC-98 emulation mode regardless of the settings in the DOSBox-X config file.

You can start DOSBox-X in PC-98 mode without any additional files apart from the DOSBox-X executable itself. Note, however, that in order for DOSBox-X to display Japanese characters (Kana, Kanji, etc.) correctly you may need to supply a font file. While optional (the internal Japanese DOS/V font will be used if no other font found, unless the TrueType font output is used, see below), it is still recommended using a font file specifically designed for PC-98. You can either use the original PC-98 FONT.ROM ROM file, or use the free alternative FREECG98.BMP included with DOSBox-X. Put the FREECG98.BMP file or the original PC-98 FONT.ROM file in the DOSBox-X directory, then DOSBox-X will render Japanese texts in the PC-98 mode using this font (if both FREECG98.BMP and FONT.ROM files are found in the directory then the latter will be used):

You can also specify a different Anex98-compatible font file with pc-98 anex86 font option in [pc98] section of the DOSBox-X config file.

If you want to use the TrueType font (TTF) output option (i.e. with output=ttf), then you will need a Japanese TrueType font for PC-98 mode. For example, you can use any of the Japanese TrueType fonts from the Migu or M+ P families:

The SarasaGothicFixed.ttf and UnifontFullMediumMono.ttf font files are also available in the DOSBox-X repository:

Specify the desired Japanese TrueType font with the font config option in [ttf] section for the TTF output, and then DOSBox-X will render the PC-98 text screen using this TTF font.

Apart from the FONT.ROM ROM image file mentioned above, there is another PC-98 ROM file named SOUND.ROM which is the ROM image of the PC-98 FM board, which may be needed by some PC-98 games to make music and sound effects. Both of these ROM images can be found online.

There are quite a few PC-98 related options in the DOSBox-X config file, such as the options to enable or disable EGC and GRCG graphical functions. These config options can be found in the [pc98] section of the DOSBox-X config file, and many of them can also be toggled in the "PC-98 options" menu group under the "Video" menu. The following config options can be found in the dosbox-x.reference.conf file, while more advanced options can be found in the dosbox-x.reference.full.conf file:

You may not need to change most config options for PC-98 mode, although you may want to take a look at the last one pc-98 anex86 font if you want to specify a different font for PC-98, and/or pc-98 force ibm keyboard layout if you are not a Japanese user. DOSBox-X will decide whether to use the Japanese keyboard layout or the U.S. keyboard layout for the PC-98 emulation based on its detection of user’s keyboard layout by default, but for earlier versions DOSBox-X always defaulted to the Japanese keyboard layout since PC-98 system was originally designed for the Japanese market, and users outside Japan who want to use the PC-98 system may want to change the setting to the default U.S. keyboard layout instead, which can be done by setting pc-98 force ibm keyboard layout to true, or it may be enabled via the Use US keyboard layout menu option in the "PC-98 options" menu group. With this enabled you will be able to use DOSBox-X’s PC-98 system more easily with the standard U.S. keyboard layout.

Once you are in DOSBox-X’s PC-98 system, you can start preparing for playing PC-98 games or running PC-98 applications. First you need to mount a drive for use with PC-98 games or applications. The drive can be mounted either from a drive or directory in the host system, or from a disk image. In general mounting drives in PC-98 mode follows the same procedures as in DOSBox-X’s standard mode, although disk images for PC-98 systems may come with HDI or FDD formats rather than the IMG format which is typically seen in a standard system. In any case you can mount the drives with either MOUNT or IMGMOUNT command as usual, or it can be done from the "Drive" menu.

An example of using MOUNT command:

An example of using IMGMOUNT command:

Once a drive is mounted, you can enter the drive directory and start the desired game or application, or boot from the drive in the case of bootable disk images. The actual steps are also similar to how they are done in DOSBox-X’s standard system. For example, you can install and run the PC-98 version of Windows 3.1 in DOSBox-X’s PC-98 system the same way as you install and run the standard version of Windows 3.1 in DOSBox-X’s default machine type.