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?)
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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.