Probably similar to NEO-SUD on the NeoGeo CD. Close to the audio hardware.
Pinouts
File:Neo-d0 pinout.png
- D0~D5: 68k data bus
- A4: 68k address line
- 4116CS: Z80 RAM /CS
- 2610*: YM2610 control lines
- OUT1~OUT6: Joypad outputs
- SDMRD/SDMRW: Z80 SM1/RAM control lines
- SDZ80*: From NEO-C1