NEC PC-8801 (PC-88) & PC-9801 (PC-98)¶
The standards of Japanese computing. The PC-88 (Z80) is the machine of Japanese RPG/AVG (Ys, Hydlide, Thexder); the PC-98 (x86) dominated Japan (business and games — eroge, and the first Touhou!). Two distinct lines, same maker. Standard period-micro repair: recap, floppies, battery.
NEC PC-9801 RX — photo by htomari, CC BY 2.0 (Wikimedia Commons).
Identification / lines¶
| Line | Key models | Year | CPU | Note |
|---|---|---|---|---|
| PC-8801 (PC-88) | mkII SR / FR / MR / FH / MH / FA / MA | 1981-85+ | Z80 @ 4-8 MHz | JP RPG/AVG; FM YM2203 (OPN) → YM2608 (OPNA) sound |
| PC-9801 (PC-98) | 9801 → VM/VX/RA/DA/BX/9821… | 1982+ | 8086 → V30/286/386/486 | JP-dominant; GDC µPD7220; FM YM2203/2608 |
| PC-6001 / PC-8001 | — | 1979-81 | Z80/µPD780 | NEC's beginnings |
(The PC Engine console is another NEC branch.)
Repair (technician)¶
- Recap: PSU and board electrolytics (the No. 1 instability source on these period machines) → Recap.
- Battery (RTC/CMOS) — especially the PC-98: a leaking battery → remove/replace, repair traces → backup batteries.
- Floppy drives (5.25″ then 3.5″): tired mechanism → Gotek/emulator; the PC-98 uses a particular 1.2 MB format.
- GDC (µPD7220) / graphics: corrupt video = VRAM + GDC → substitution.
- FM sound: YM2203/YM2608 (a sound card on some 98s) — sound-stage diagnosis.
- Video output: analog RGB (24/31 kHz per model) → a suitable monitor / mods.
Common faults¶
| Symptom | Likely cause | Lead |
|---|---|---|
| Instability / crashes | PSU/board caps | Recap |
| Corrosion / wrong clock (98) | leaked CMOS battery | Remove, repair traces |
| Floppy not read | mechanism / format | Clean, Gotek |
| Corrupt video | VRAM / GDC | Substitute VRAM, test GDC |
| Silent sound | YM2203/2608 | Sound-stage diagnosis |
Modernisation & mods — what to buy, how¶
Leaking CMOS/RTC battery + recap
PC-98: the CMOS/RTC battery leaks and eats the board → remove it, repair traces, replace with lithium + diode. Recap board/PSU; change drive belts (unreadable disks); clean contacts.
Modern storage - PC-98: SCSI → BlueSCSI / SCSI2SD 🟢 (many PC-98 are SCSI), CF on IDE (later models) 🟢; floppy → Gotek + FlashFloppy or HxC (2HD/2DD) 🟡. PC-88: Gotek/SD 🟡.
Video - Analog RGB 24/31 kHz output (PC-98) 🟢 → OSSC / RetroTINK or RGB2HDMI; connector adapters per model.
⚠️ Do not host ROMs/games — method only.
See also¶
- Sharp X68000 · MSX · Fujitsu FM Towns · PC Engine (NEC console) · Recap.
Sources & attribution¶
- Photo NEC PC-9801 RX — htomari, CC BY 2.0, Wikimedia Commons — https://commons.wikimedia.org/wiki/File:NEC_PC-9801_RX_Personal_Computer.jpg
- Wikipedia — PC-8801 & PC-9801 (Z80 / x86, GDC µPD7220, YM2203/2608, lines) — CC-BY-SA — https://en.wikipedia.org/wiki/PC-98
- Established NEC community knowledge (recap, PC-98 CMOS battery, 1.2 MB floppy format) — synthesis.
Review & corrections
How this space is used
Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.
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