NEC PC-9801-86 Sound board

Image: PC-9801-86 panel

NEC PC-9801-86
Retail price 25,000 yen
Manufacturer NEC
Available date 1993 - 1996 (?)
System requirement NEC PC-9800 series, faster than i80286 10 MHz
Supported OS MS-DOS 5.0 and later
OS/2 Warp V3, V4
Windows 3.1, 95, 98, NT 3.5, 3.51, 4.0
Features Yamaha YM2608 FM synth (no ADPCM support)
PCM recording & playing (max 44.1 kHz / 16 bit / 2 ch)
I/O panel Mic Input (1 ch)
Line Input (2 ch)
Mini jack out 2 x 2 ch
DC 12 V Power Input
Contents Sound board
2 x Stereo audio cables
Microphone (PC-9821A-U01)
AV Sound Driver Disk (5.25" FD x 1、3.5" FD x 1)
Users manual
Notes If all other slots use +12V, ext DC power supply is required.

PC-9801-86 Sound board
According to S/N, this board was made in August 1996. PCB number (?) is G8NQY. (Note: First digit of S/N means the last digit of manufactured year, and the second means its month, but X = October, Y = November, Z = December)

The PC-9801-86, often called "86 board" (86ボード) or "86 sound" (86音源), came out in 1993. It has Yamaha's YM2608 (OPNA) FM synth chip, PCM sound buffers (often called "86PCM") and a compatiblity with its predecessor standard "PC-9801-26K". PC98 gamers should own it because it was supported by most PC98 DOS games. As of 2016, the 86 board is priced at $70 - $100 in Yahoo Japan auction.

  1. Three-terminal regulator for the external power supply (PC-9801-73-AC).
  2. 8 positions DIP switches to configure hardware resources.
  3. NEC 128KB ROM? - Same BIOS ROM as PC-9801-26K, both are used for N88-BASIC(86).
  4. Bus controller IC
  5. YAMAHA YM3433B - PCM data/channel separater.
  6. Burr-Brown PCM61P x 2 - 18 bit D/A converter for PCM sound.
  7. NEC uPC1406HA x 6 - Controlling sound volumes.
  8. Oki 32KB DRAM - FIFO buffers for PCM playing.
  9. FM Synthesizer chip


Rear panel


The connector marked as "CN9 AGING" is a test plug. This is not an audio line. PSG sound is output from Pin 27, and then mixed with the FM sound in the analog circuit. So, some compatible boards play FM / PSG sounds with a different volume.

An normal 86 board is a bit noisy. I tried Yasuma's modification, and it became noiseless and dynamic sound which is better than PC98 emulator's. (Put 16V/22uF capacitor between Pin 1 and 2 of YM3016, remove XRU4066BF chip and bypass 2 lines.)

DAC at PCM circuit (Burr-Brown PCM61P, Dynamic range 108dB)


Compatible boards from third parties:

Idle Japan Super Sound 10
? 19,800 yen "PC-9801-26K" compatible (OPN), RCA-out 2ch x 1,
Mini jack out 2ch x 1, On-board speaker x 1,
Idle Japan Speak Board
1991? 49,800 yen "PC-9801-73" FM only compatible(OPNA, ADPCM),
ADPCM rec&play (max. 32KHz/8bit/2ch),
RCA-in 2ch x 1, RCA-out 2ch(+1ch), JOYSTICK x 1
Qvision WaveMaster Jun.1995 26,800 yen "PC-9801-86" fully compatible(OPNA + PCM) + SCSI I/F,
Mic input, Line input (2ch)、Mini jack out 2ch x 1、
JOYSTICK x 1、SCSI port x 1
Qvision MidiMaster Jun.1995 12,800 yen Optional daughter board for WaveMaster.
It contains OPL4 FM synthesizer, supports GM MIDI.

The PC-9801-73 came out in 1991, 2 years before the 86 board. It had a YM2608 FM synth, ADPCM sound buffers, PCM sound buffers and a DSP chip with 4 audio channel outputs. It was not popular due to its high price. The 86 board didn't have a fully compatibility with the 73 board, but you won't be in trouble because most applications used it as the 86 board.

Advert of Speak Board and Super Sound 10.

Dip switch settings (O=Open (Off), X=Closed (On))

8 positions dip switch

1 : I/O port address
2 : Use sound BIOS ROM
3,4 : Interrupt level
5 : Use interrupt
6-8 : Sound Function ID

SW 説明 状態 設定
1 I/O port address O 288h-28Eh
X 188h-18Eh
2 Use sound BIOS O Disabled (Not allocate)
X Enabled (CC000h)
3,4 Interrupt level OO INT0 (IRQ3)
5 Use interrupt O Disabled
X Enabled
6,7,8 Sound Function ID
(SW1=X : 4,
SW1=O : 5)
XXX 0(PC-98DO+)
OXX 1(PC-98GS)
XOX 2(PC-9801-73,188h)
OOX 3(PC-9801-73,288h)
XXO 4(PC-9801-86,188h)
OXO 5(PC-9801-86,288h)
XOO 6(PC-9821Nf/Np)
OOO 7(Mate-X PCM)

Default setting : XXXXXXXO

You shouldn't change these settings except avoiding resource conflicts. The Sound Function ID is only refered to by applications, so it doesn't mean you can change the function of the board. The PC-9801Xn released in September 1994 and laters have the WSS-PCM that is not compatible with the 86 board. It causes resource conflicts. When you use the 86 board on these machines, you must disable the WSS-PCM by using the System Setup Menu. Refer to System Setup Menu [NEC PC98].

Sound drivers

Software Date How to get its device driver
N88-BASIC(86),N88-日本語BASIC(86) - Use Sound ROM (26K compatible only)
N88-日本語BASIC(86)(MS-DOS版)(Ver6.1)マルチメディア対応 1991/11 Supported by default.
N88-日本語BASIC(86)(MS-DOS版)(Ver6.2) 1994/01
日本語MS-Windows(Ver.3.0) 1991/02 Require an optional driver software.
日本語MS-Windows(Ver.3.0A) 1991/12
日本語MS-DOS(Ver5.0) 1991/11 Driver disk comes with the board.
日本語MS-DOS(Ver5.0A) 1992/11
日本語MS-DOS(Ver5.0A-H) - Included in the operating system.
日本語MS-Windows(Ver.3.0A-H) -
日本語MS-Windows(Ver.3.0B) 1993/02
Microsoft Windows 3.1 1993/05
MS-DOS 6.2 1994/12
OS/2 Warp V3 日本語版 1994/12
OS/2 Warp V4 日本語版 1996/12
Microsoft Windows NT Workstation 3.5 1994/12
Microsoft Windows NT Workstation 3.51 1995/11
Microsoft Windows NT Workstation 4.0 1996/12
Microsoft Windows 95 1995/10
Microsoft Windows 98 1998/06
Microsoft Windows 98 Second Edition 1999/08

Many PC98 DOS games didn't use the NEC's driver (AVSDRV.SYS) because there are some good shareware and freeware drivers better than NEC's. Usually, the driver comes with the software, so you need not do anything.

Here I'll introduce you some famous sound drivers.

Related pages

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