NEC PC-9801-26K Sound Board
PC-9801-26K Sound Board for NEC PC-98 series.
| NEC PC-9801-26/26K | |
| Retailed Price | 25,000 yen |
| Released Date | Jul.1985(PC-9801-26) |
| Nov.1986 (PC-9801-26K) | |
| System requirements | NEC PC-9800 Series(8086、V30 CPU only) (PC-9801-26) |
| NEC PC-9800 Series (PC-9801-26K) | |
| Supported OS | N88-BASIC(86) |
| Microsoft Windows 3.1 | |
| Functions | OPN(FM 3 channels、PSG 3 channels、8 octaves, monophonic) |
| I/O | 1 x RCA output 1ch |
| 1 x 3.5mm mono output 1ch | |
| On-board speaker | |
| Output connector for internal system speaker | |
| 2 x Atari Joystick connector | |
| Contents | Sound board |
| Cable for internal system speaker | |
| Cautions when exporting (Paper) | |
| Users manual | |
| Notice | You cannot use this with other sound boards. |
Manufactured on Dec.1987. PCB number(?) is G9WYK
PC-9801-26 Sound Board was introduced with PC-9801VF/9801VM in July 1985. It had the FM synthesizer Yamaha YM2203, that was also contained in PC-8801mkIISR. PC-9801-26K was released in 1986 to support PC-9801VX (introduced in Oct.1986, came with 80286 CPU) which changed the bus timing, It had been used as the standard sound board for 7 years until the successor PC-9801-86 came out in 1993.
- Sound output connector for internal system speaker.
- Jumper switches - Set ROM address, interrupt, I/O port.
- Mitsubishi 8KB EPROM x 2 - Sound BIOS for N88-BASIC(86)
- YAMAHA YM2203 - FM synthesizer
- Center big one is an onboard speaker.
Removed an on-board speaker.
YAMAHA YM2203(OPN) and EPROM
Almost chips you can see are TTL-IC. DAC is YM3014D. OP amps are two NJM072D and one LM386N-1, they are put under the speaker.
Strap switch settings
5 jumpers(6A2) : Sound BIOS ROM address
1-10 : C8000h
2-9 : CC000h (default)
3-8 : D0000h
4-7 : D4000h
5-6 : Disable ROM(Detached)
3 pin x 2 jumpers(6A1, 6A3) : Interrupt level
2-3, 2-3 : INT0
2-3, 1-2 : INT4
1-2, 1-2 : INT5 (default)
1-2, 2-3 : INT6
2 jumpers(6A4) : I/O port address
1-4 : 88h
2-3 : 188h (default)