emulator: nekop2
type: libretro
core_classification: community_fork
source: "https://github.com/libretro/libretro-meowPC98"
upstream: "https://np2.yui.ne.jp (dead; source preserved in libretro repo)"
profiled_date: "2026-03-24"
core_version: "0.86"
display_name: "NEC - PC-98 (Neko Project II)"
cores: [nekop2]
systems: [pc-98]

# Neko Project II (NP2) by Yui, ported to libretro by meepingsnesroms.
# PC-9801/9821 emulator (80286/IA-32 CPU). All files load from <system>/np2/.
# The libretro shim sets np2cfg.biospath to "<system>/np2/" and
# file_setcd() to the same path (libretro/libretro.c:856-864,196).
#
# BIOS_SIMULATE is hardcoded (bios/bios.c:26), so the core always has
# a built-in BIOS simulator and ITF ROM is never loaded from disk.
# Font data falls back to built-in 8x8 tables. Sound ROM falls back
# to a 9-byte stub. IDE/SCSI/SASI all have built-in stubs.
#
# This is NOT the same core as np2kai. Different repo, different
# feature set (no fmgen, no IDE/PCI/GPIB ROM loading, no itf.rom).
# BIOS path is np2/, not np2kai/.
#
# .info declares firmware_count=0, which is misleading — the core
# loads multiple BIOS/font/sound files but all have built-in fallbacks.

files:
  # -- Main BIOS ROM --
  # Loaded in bios/bios.c:232-235 via getbiospath(). 96 KB (0x18000)
  # mapped at 0xe8000. Without this, the built-in BIOS simulator
  # (nosyscode + BIOS_SIMULATE) is used.
  - name: "bios.rom"
    path: "np2/bios.rom"
    required: false
    hle_fallback: true
    note: >
      PC-9801 system BIOS ROM (96 KB). The core boots without it using
      the built-in BIOS simulator, but some software requires the real BIOS.
    source_ref: "bios/bios.c:232-235, common/strres.c:53"

  # -- PC-9821 extension BIOS --
  # Loaded in bios/bios.c:262-266 via getbiospath(). 8 KB (0x2000)
  # at 0xd8000. Only compiled when SUPPORT_PC9821 is defined
  # (libretro/compiler.h:169).
  - name: "bios9821.rom"
    path: "np2/bios9821.rom"
    required: false
    note: >
      PC-9821 extension BIOS ROM (8 KB). For PC-9821 mode support.
      Mapped at 0xd8000.
    source_ref: "bios/bios.c:262-266, libretro/compiler.h:169"

  # -- Font file --
  # Set in libretro.c:862 as "<system>/np2/font.bmp".
  # font_load() in font/font.c:113 determines type by extension:
  # .bmp = PC98 format, FONT.ROM = V98 format.
  # Without any font file, built-in fontdata_8 provides 8x8 ASCII only.
  - name: "font.bmp"
    path: "np2/font.bmp"
    required: false
    hle_fallback: true
    aliases: ["FONT.ROM"]
    note: >
      PC-98 font bitmap (288 KB). Required for correct Japanese kanji display.
      Without this, only basic ASCII renders using built-in 8x8 data.
      FONT.ROM (V98 format) is also accepted.
    source_ref: "libretro/libretro.c:862, font/font.c:113, font/fontdata.c:12"

  # -- Sound BIOS ROM --
  # Loaded by soundrom_load() via loadsoundrom() in sound/soundrom.c:21-55.
  # Filename built as "sound" + optional board name + ".rom".
  # Board-specific variants: sound26.rom (PC-9801-26K), sound86.rom (86),
  # sound118.rom (118), soundSPB.rom (Speak Board), sound14.rom (14).
  # The code tries the board-specific name first, falls back to sound.rom.
  # 16 KB (0x4000). Fallback: 9-byte defsoundrom stub.
  - name: "sound.rom"
    path: "np2/sound.rom"
    required: false
    hle_fallback: true
    note: >
      FM sound board BIOS ROM (16 KB). The core tries board-specific
      variants first (sound26.rom, sound86.rom, sound118.rom, soundSPB.rom,
      sound14.rom) then falls back to sound.rom.
    source_ref: "sound/soundrom.c:15-16,21-55,65-78"

  # -- YM2608 OPNA rhythm samples --
  # Loaded by rhythm_load() in sound/rhythmc.c:60-71 via getbiospath().
  # No fmgen engine in this core — only lowercase filenames are used.
  - name: "2608_bd.wav"
    path: "np2/2608_bd.wav"
    required: false
    note: "YM2608 OPNA rhythm sample: bass drum"
    source_ref: "sound/rhythmc.c:11,60-71"

  - name: "2608_sd.wav"
    path: "np2/2608_sd.wav"
    required: false
    note: "YM2608 OPNA rhythm sample: snare drum"
    source_ref: "sound/rhythmc.c:12"

  - name: "2608_top.wav"
    path: "np2/2608_top.wav"
    required: false
    note: "YM2608 OPNA rhythm sample: top cymbal"
    source_ref: "sound/rhythmc.c:13"

  - name: "2608_hh.wav"
    path: "np2/2608_hh.wav"
    required: false
    note: "YM2608 OPNA rhythm sample: hi-hat"
    source_ref: "sound/rhythmc.c:14"

  - name: "2608_tom.wav"
    path: "np2/2608_tom.wav"
    required: false
    note: "YM2608 OPNA rhythm sample: tom"
    source_ref: "sound/rhythmc.c:15"

  - name: "2608_rim.wav"
    path: "np2/2608_rim.wav"
    required: false
    note: "YM2608 OPNA rhythm sample: rim shot"
    source_ref: "sound/rhythmc.c:16"

  # -- SCSI controller BIOS --
  # Loaded in cbus/scsiio.c:219 via file_open_rb_c(). 16 KB (0x4000).
  # Falls back to built-in scsibios[] stub.
  - name: "scsi.rom"
    path: "np2/scsi.rom"
    required: false
    hle_fallback: true
    note: >
      SCSI controller BIOS ROM (16 KB). The core includes a built-in
      SCSI BIOS stub as fallback.
    source_ref: "cbus/scsiio.c:208-233"

  # -- SASI controller BIOS --
  # Loaded in cbus/sasiio.c:453 via file_open_rb_c(). 4 KB (0x1000).
  # Falls back to built-in sasibios[] stub.
  - name: "sasi.rom"
    path: "np2/sasi.rom"
    required: false
    hle_fallback: true
    note: >
      SASI controller BIOS ROM (4 KB). The core includes a built-in
      SASI BIOS stub as fallback.
    source_ref: "cbus/sasiio.c:442-465"