PC-98

The NEC PC-9800 series are 16/32-bit computers from NEC Corporation. It marked a shift away from the Z80-based PC-88 to the x86 architecture. Just like their predecessor series, they were known for their unique sound hardware by YAMAHA, and games kept the systems popular. They were likely never released outside Japan in the series lifespan, except for the APC III.

Status

ReactOS PC-98 port is under slow development.

Help in testing

You can run ReactOS only on i586 class CPUs and above, so that means you can run it on any of the models with a Pentium CPU. Keep in mind ReactOS requires at least 64 MB of RAM. It's recommended to use NEC PC-9821Ra43 with a Celeron CPU @ 433 MHz which is the last model in the series. Currently ReactOS only supports booting from a 1.44 MB 3.5" internal floppy drive. After booting up using the diskette, FreeLoader loads a boot image from any of supported devices: IDE CD-ROM, SCSI CD-ROM or MO.

You need the following steps:

• Check out this article to learn more about the testing process.
• You should be able to compile ReactOS.
• Run the following command configure -DSARCH=pc98 before compilation, to set target platform as PC-98.
• Execute for build pc98bootfdd target to create a bootable floppy image. The created image will be placed on /output folder/PC98/.
• Build and burn a LiveCD/BootCD ISO image.
• Insert the floppy disk, medium, and boot the ReactOS.

Any test results will be useful to improve PC-98 port.

Hardware

The PC-9800 series use a custom hardware C-bus (later models do use PCI) and a firmware that is completely different from a Standard PC BIOS, so a new HAL should be created.

In Windows 2000 there are four known HALs for this platform:

File Name	Hardware ID String	HAL Name
hal98up.dll	nec98Notmr_up	PC-9800 System Clock 10MHz
hal98tmr.dll	nec98tmr_up	PC-9800 System Clock 10MHz (support 2nd Timer)
hal98apc.dll	nec98mps_up	NEC PC-9800 APIC HAL
hal98mp.dll	nec98mps_mp	NEC PC-9800 MPS HAL

PC-9800 series hard disks are usually formatted with FAT12, but they use 1024 bytes per sector as opposed to the PC's 512.

Emulation

• Neko Project 21/W is a NEC PC-9821 series emulator that can run Windows 2000. It potentially can be used for ReactOS PC-98 port development and testing.
• SL9821 is a NEC PC-9821 series emulator with partial compatibility with Windows 2000 (no sound, no network, IDE issues). ROM image files are required to run SL9821.
• QEMU/9821 also exists, but it seems not maintained anymore and does not run Windows 2000.
• DOSBox-X and MAME can emulate a wide range of PC-98 hardware.

See Also

• Windows 2000 booting on NEC Lavie PC-9821 Nr15 (Pentium, 96 MB RAM)
• Windows 2000 booting on NEC PC-9821 RvII26 (SSD, 640 MB RAM)
• Linux/98 (Plamo Linux) on NEC PC-9821 V12 (96 MB RAM)
• Neko Project 21/W (in Japanese)
• Neko Project 21/W - Windows 2000 installation guide (in Japanese)
• SL9821 (in Japanese)
• QEMU/9821 for Windows (2012/08/20)
• ROMs for QEMU/9821
• DOSBox-X
• MAME
• Overview of PC-98 hardware and BIOS architecture
• Example output of the lspci command, and another one (pciconf)
• FreeDOS(98) kernel source code
• Discussion on BetaArchive
• Video: Installing Windows 2000 in Neko Project 21 (PC-98) (Better quality video can be found there.)

ReactOS ports‎
In active development	Intel IA-32 (x86) | AMD64 (x64)
In slow development	NEC PC-98 (x86) | Xbox (x86)
Unmaintained	ARM32 (armv7) | PowerPC (ppc) | OLPC (x86)
Missing ports that Windows has	ARM64 (aarch64) | Intel IA-64 (Itanium) | SGI 320/540 (x86) | DEC Alpha (axp) | MIPS