Below is a curated library of software and data that was uploaded to the Discord server. Downloading from a conventional site is not only more convenient, it's also a form of redundancy.
All resources provided before August 2024 will be hotlinks to the original repository at LainNet. Future uploads will be directory hosted here.

286BOOK_27C1024_A05CLBK.bin
286BOOK_27C1024_A08CLBK.bin
386BOOK_27C1024_A03CLB2.bin
Epson PC-286BOOK and PC-386BOOK BIOSes

ORCAD_3.10_for_NEC.rar No Description
MS-LAN_ManageFor_PC-9800.rar No Description
CorpseP.rar Corpse Party, Revision 1
CorpseVer2.rar Corpse Party, Revision 2
CorpseLast.rar Corpse Party, Final Revision (4?)
Mate-R_bible.pdf The Mate-R Bible, written by @wildcat_300104
COMMANDCOM.ZIP Mooliecool's English translated COMMAND.COM for MS-DOS 6.20
as2.bin PC-9821 AS2/AP2 BIOS.
Archive.zip
bios.zip
UNDOCUMENTED 9801/9821 Vol.1, Shift-JIS and UTF-8 Encoded
VEM13113.zip Final version of the VEM486 memory manager. Compatible with Windows.
PCCARD_98note.zip PC Card drivers for 98Note series machines.
win98boot.fdi Boot disk I made that's suitable for installing Win98(SE). It comes with a CD driver, FDISK, COPY and FORMAT, the bare minimum needed to accomplish an installation.
wsna_31.exe MELCO WSN-A2F/A4F driver package for Win3.1. Useful for running 3.1 in a higher resolution on np21/w.
epc98lt.rar
epc98ha.rar
Common Source Code Project PC-98LT and PC-98HA emulators with appropriate BIOS dumps.
PC-PTOS_VER2.4.rar
PC-PTOS_VER3.0.rar
PC-PTOS versions 2.4 and 3.0 (startup disks missing)
MS-Windows_386.rar Microsoft Windows 386/2.11
1138_v2.stl FD1138 drive door STL model for 3D printing.
PC-9821_XnXpXs_Window_accelerater_Driver_for_Windows_3.1.rar Xn/Xp/Xs Window Accelerator drivers for Windows 3.1
cscp_binaries.7z
cscp_ROMs.7z
Common Source Code Project PC-98 emulator binaries and ROMs.
OPN3.kicad_sch
OPN3.jed
OPN3.PLD
Simple C-Bus OPL3 board KiCAD sch and PLD data by Ethylene.
LHA-301_V1.05.bin LHA-301 BIOS revision v1.05
LHA-301_V1.07.bin LHA-301 BIOS revision v1.07
PCISETUP.rar PCISETUP 1.50, from the Valuestar V166/V200 system restore disks
PC-9821Ra20_PCI.rar PCISETUP 1.40 image, suitable for PC-9821Ra i686 machines (1996-2000)
pc9821cBusCovermk1.5.stl C-Bus slot cover STL by Meowmaster.
TASM.EXE
TLINK.EXE
Turbo Assembler 2.51 and Turbo Link 4.0. These have been provided to me by, believe it or not, Naoto Niida from C-Lab, and I've decided to share these here because we don't have them dumped anywhere (We only have TASM 2.0).
MUE.EXE C-Lab's Rusty/Totsugeki Mix level layout editor for internal use. Yes, Niida has in fact given me permission to redistribute it since it is not under any copyright.
DOS5.00A-H_installer.zip MS-DOS 5.00A-H installation media created from PC-9821 recovery disks. Thanks, mctek!
vgbpc98.zip Virtual GameBoy 0.6 PC-98 DOS port by Shinya Yamamoto
gainax98.zip
pmplus01.lzh
Princess Maker debug patch and other Gainax game patches.
PC-9821Cx3.rar Full dump of the PC-9821 Cx3 BIOS.
FS.rar FS file manager.
CPM.rar CP/M80 Simulator.
spkqq341.lzh
spkqq333.zip
SPK98/SPKQQ 3.41 and 3.33. Serial key information is as follows:
id:HCW35263 pw:9408-0481-R326
9512-0481-A000:SGT02603
Seri.txt Massive collection of serial keys for various Japanese software.
NEC_CDR_52_TMS27C256.BIN NEC CDR-52 (PC-9821Ce CD drive) ROM
WYKA01_M5L2764K.BIN
WYKA02_M5L2764K.BIN
NEC PC-9801-26K Sound ROMs
PC_9821Ce_NYF5200_D27C4000D-15.BIN NEC PC-9821Ce BIOS ROMs
Qvision-WaveStar_REV-WST07A_MX27C256DIP28.rar QVision WaveStar BIOS, final revision
HSB37PAK.LZH Will.Broke.It's updated HSB pack.
qvision_all_in_one.rar
qvision_roms.rar
QVIsion ROM and driver collection
PC9801BX4BANK.zip PC-9801BX4 banked BIOS ROMs
MadoMonogatari2EN.zip Madou Monogatari 2 - Unofficial English translation - Prepatched
Madou_Monogatari_2_PC98_ENG_V1.0.7z Madou Monogatari 2 - Unofficial English translation - Patches only, as distributed by the translation group Eight Mansions
SCSI_ROM_Collection.zip MCtek's collection of BIOS ROMs for PC-98 SCSI cards. Some even have DIV0ROM patches.
PC-9801-86交換用電解コンデンサセット_説明書.pdf PC-9801-86 capacitor set - replacement instructions
GDC31.7z drachen6jp's GDC 31kHz configuration utility that works on PC-9801s.
SODICK_FD.zip System, MAP and User disks for Sodick EDM Mark XI CNC machines, powered by PC-9801 UV11 computers.