WR550400/WR550402 pinout

         .---v---.
   D7 -> |01   18| <- D0
   D1 -> |02   17| ------------[R=750k]-+
   D6 -> |03   16| -> MAIN CLK----------+
   D2 -> |04   15| -- GND
   D5 -> |05   14| -> SONG3 PLAYED
   D3 -> |06   13| -> SONG3 FINISHED STROBE
   D4 -> |07   12| -> DATA
  +5V -  |08   11| -> CLK1 (for audio data ?)
AUDIO <- |09   10| -> CLK2 (for meta data?)
         `-------`
     WR550400/WR550402

Notes:

• Those 2 chips were used in bootleg version of Moe Pro! Saikyou-hen Baseball [1], along with pirate VRC4 chip. Original game used Jaleco SS88006 along with D7756C ADPCM Speech Chip [2]
• Each of those 2 chips contains different set of 8 audio samples, used in game.
• Vendor logo printed on ICs suggest that the manufacturer was Winbond,
• Forcing rising edge on one of its D0..D7 inputs enables playback adequate audio sample
• The output "analog" audio has 32-voltage-levels,
• Along with the analog audio, there is some digital data transmitted on pins 12/11/10
• Pin 14 is high for the whole time when D2 audio sample is played,
• Pin 13 goes high for the last 0.5ms when D2 audio sample is played.