MMC5 Audio
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Contents |
[edit] Overview
Nintendo's MMC5 mapper provides extra sound output, consisting of two pulse wave channels and a PCM channel. The pulse wave channels behave almost identically to the native pulse channels in the NES APU.
[edit] Pulse 1 ($5000-$5003)
These registers manipulate the MMC5's first pulse wave channel, which functions identically to those found in the NES APU except that it lacks sweep support.
[edit] Pulse 2 ($5004-$5007)
These registers manipulate the MMC5's second pulse channel.
[edit] Unknown ($5010, read/write)
[edit] Write
7 bit 0
---- ----
xxxx xxxC
|
+- Unknown (enable output of alternate PCM channel?)
[edit] Read
7 bit 0 ---- ---- ???? ???? |||| |||| ++++-++++- Unknown
This register is implemented - reading it does not return open bus as other write-only registers do. Its function, however, is not yet known.
[edit] Raw PCM ($5011)
7 bit 0 ---- ---- WWWW WWWW |||| |||| ++++-++++- 8-bit PCM data
This functions exactly the same as the NES APU's register $4011, except that all 8 bits are used.
[edit] Status ($5015, read/write)
This register is analagous to the APU Status register found within the NES at $4015, except that only the bottom 2 bits are used (with the MMC5's two pulse channels).
