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31 lines
1.2 KiB
Markdown
31 lines
1.2 KiB
Markdown
# Famicom Disk System
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the Famicom Disk System is an expansion device for the Famicom (known as NES outside Japan), a popular console from the '80s.
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as it name implies, it allowed people to play games on specialized floppy disks that could be rewritten on vending machines, therefore reducing the cost of ownership and manufacturing.
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it also offers an additional 6-bit, 64-byte wavetable sound channel with (somewhat limited) FM capabilities, which is what Furnace supports.
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# effects
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- `10xx`: **change wave.**
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- `11xx`: **set modulation depth.**
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- `12xy`: **set modulation speed high byte and toggle on/off.**
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- `x` is the toggle. a value of `1` turns on the modulator.
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- `y` is the speed.
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- `13xx`: **set modulation speed low byte.**
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- `14xx`: **set modulator position.**
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- `15xx`: **set modulator wave.**
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- `xx` points to a wavetable. it should (preferably) have a height of 7 with the values mapping to:
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- 0: +0
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- 1: +1
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- 2: +2
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- 3: +3
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- 4: reset
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- 5: -3
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- 6: -2
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- 7: -1
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- why is this mapping so unnatural? because that's how DefleMask does it (yeah, as you may have guessed this effect is mostly for compatibility reasons)...
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# info
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this chip uses the [FDS](../4-instrument/fds.md) instrument editor.
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