furnace/doc/7-systems/snes.md

# Super Nintendo Entertainment System (SNES) / Super Famicom

the successor to NES to compete with Genesis, packing superior graphics and sample-based audio.

its Sony-developed audio system features a DSP chip, SPC700 CPU, and 64KB of dedicated SRAM used by both.
this whole system itself is pretty much a separate computer that the main CPU needs to upload its program and samples to.

Furnace communicates with the DSP directly and provides a full 64KB of memory. this memory might be reduced excessively on ROM export to make up for playback engine and pattern data. you can go to window > statistics to see how much memory your samples are using.

some notable features of the DSP are:
- pitch modulation.
- a built in noise generator, useful for hi-hats, cymbals, rides, effects, among other things.
- per-channel echo, which unfortunately eats up a lot of memory but can be used to save channels in songs.
- an 8-tap FIR filter for the echo, which is basically a procedural low-pass filter that you can edit however you want.
- sample loop, but the loop points have to be multiples of 16.
- left/right channel invert for surround sound.
- ADSR and gain envelope modes.
- 7-bit volume per channel.
- sample interpolation, which is basically a low-pass filter that gets affected by the pitch of the channel.

Furnace also allows the SNES to use wavetables (and the wavetable synthesizer) in order to create more 'animated' sounds, using less memory than regular samples.

## effects

- `10xx`: **set waveform.**
- `11xx`: **toggle noise mode.**
- `12xx`: **toggle echo on this channel.**
- `13xx`: **toggle pitch modulation.** frequency modulation by the previous channel's output. no effect on channel 1.
- `14xy`: **toggle inverting the left or right channels.** `x` is left, `y` is right.
- `15xx`: **set envelope mode.** see gain chart below for `1` through `5`.
  - `0`: ADSR mode.
  - `1`: gain (direct). volume holds at one level.
  - `2`: linear decrement. volume lowers by subtractions of 1/64.
  - `3`: exponential decrement. volume lowers by multiplications of 255/256.
  - `4`: linear increment. volume rises by additions of 1/64.
  - `5`: bent line (inverse log) increment. volume rises by additions of 1/64 until 3/4, then additions of 1/256.
- `16xx`: **set gain.** `00` to `7F` if direct, `00` to `1F` otherwise.
- `18xx`: **enable echo buffer.**
- `19xx`: **set echo delay.** range is `0` to `F`.
- `1Axx`: **set left echo channel volume.**
- `1Bxx`: **set right echo channel volume.**
- `1Cxx`: **set echo feedback.**
  - all of these are signed numbers.
  - `00` to `7F` for 0 to 127.
  - `80` to `FF` for -128 to -1.
  - setting these to -128 is not recommended as it may cause echo output to overflow and therefore click.
- `1Dxx`: **set noise generator frequency.** range is `00` to `1F`. see noise frequencies chart below.
- `1Exx`: **set left dry / global volume.**
- `1Fxx`: **set right dry / global volume.**
  - these do not affect echo.
- `20xx`: **set attack.** range is `0` to `F`.
- `21xx`: **set decay.** range is `0` to `7`.
- `22xx`: **set sustain.** range is `0` to `7`.
- `23xx`: **set release.** range is `00` to `1F`.
  - these four are only used in ADSR envelope mode. see ADSR chart below.
- `3xyy`: **set echo filter coefficient.**
  - `x` is the coefficient from 0 to 7.
  - `yy` is the value (signed number).
    - `00` to `7F` for 0 to 127.
    - `80` to `FF` for -128 to -1.
  - note: be sure the sum of all coefficients is between -128 and 127. sums outside that may result in overflow and therefore clicking.
  - see [SnesLab](https://sneslab.net/wiki/FIR_Filter) for a full explanation and examples.

## info

this chip uses the [SNES](../4-instrument/snes.md) instrument editor.

when two channels are joined for pitch modulation, the channel bar will show `mod` on a bracket tying them together.

## channel status

the following icons are displayed when channel status is enabled in the pattern view:

- envelope/gain status:
  - ![direct gain, envelope off](status-SNES-gain-direct.png) direct gain
  - ![linear gain decrease](status-SNES-gain-dec-lin.png) linear gain decrease
  - ![logarithmic gain decrease](status-SNES-gain-dec-log.png) logarithmic gain decrease
  - ![linear gain increase](status-SNES-gain-inc-lin.png) linear gain increase
  - ![bent-line gain increase](status-SNES-gain-inc-bent.png) bent-line gain increase
  - ![envelope attack](status-SNES-env-A.png) envelope attack
  - ![envelope decay](status-SNES-env-D.png) envelope decay
  - ![envelope sustain](status-SNES-env-S.png) envelope sustain
  - ![envelope release](status-SNES-env-R.png) envelope release

## chip config

the following options are available in the Chip Manager window:

- **Volume scale**: scale volumes to prevent clipping/distortion.
- **Enable echo**: enables the echo buffer.
- **Initial echo state**: selects which channels will have echo applied.
- **Delay**: sets echo length.
- **Feedback**: sets how much of the echo output will be fed back into the buffer.
- **Echo volume**: sets echo volume.
- **Echo filter**: adjusts echo filter.

## ADSR

| attack | 0→1 time | decay | 1→S time | sustain | ratio | release | S→0 time
| -----: | -------: | ----: | -------: | ------: | :---: | ------: | -------:
|   `00` |    4.1s  |  `00` |    1.2s  |    `00` |  1/8  |    `00` |        ∞
|   `01` |    2.5s  |  `01` |    740ms |    `01` |  2/8  |    `01` |      38s
|   `02` |    1.5s  |  `02` |    440ms |    `02` |  3/8  |    `02` |      28s
|   `03` |    1.0s  |  `03` |    290ms |    `03` |  4/8  |    `03` |      24s
|   `04` |    640ms |  `04` |    180ms |    `04` |  5/8  |    `04` |      19s
|   `05` |    380ms |  `05` |    110ms |    `05` |  6/8  |    `05` |      14s
|   `06` |    260ms |  `06` |     74ms |    `06` |  7/8  |    `06` |      12s
|   `07` |    160ms |  `07` |     37ms |    `07` |   1   |    `07` |     9.4s
|   `08` |     96ms |       |          |         |       |    `08` |     7.1s
|   `09` |     64ms |       |          |         |       |    `09` |     5.9s
|   `0A` |     40ms |       |          |         |       |    `0A` |     4.7s
|   `0B` |     24ms |       |          |         |       |    `0B` |     3.5s
|   `0C` |     16ms |       |          |         |       |    `0C` |     2.9s
|   `0D` |     10ms |       |          |         |       |    `0D` |     2.4s
|   `0E` |      6ms |       |          |         |       |    `0E` |     1.8s
|   `0F` |      0ms |       |          |         |       |    `0F` |     1.5s
|        |          |       |          |         |       |    `10` |     1.2s
|        |          |       |          |         |       |    `11` |    880ms
|        |          |       |          |         |       |    `12` |    740ms
|        |          |       |          |         |       |    `13` |    590ms
|        |          |       |          |         |       |    `14` |    440ms
|        |          |       |          |         |       |    `15` |    370ms
|        |          |       |          |         |       |    `16` |    290ms
|        |          |       |          |         |       |    `17` |    220ms
|        |          |       |          |         |       |    `18` |    180ms
|        |          |       |          |         |       |    `19` |    150ms
|        |          |       |          |         |       |    `1A` |    110ms
|        |          |       |          |         |       |    `1B` |     92ms
|        |          |       |          |         |       |    `1C` |     74ms
|        |          |       |          |         |       |    `1D` |     55ms
|        |          |       |          |         |       |    `1E` |     37ms
|        |          |       |          |         |       |    `1F` |     18ms

reference: [Super Famicom Development Wiki](https://wiki.superfamicom.org/spc700-reference#dsp-voice-register:-adsr-1097)

## gain

value | linear inc. | bent line inc. | linear dec. | exponent dec.
----: | ----------: | -------------: | ----------: | ------------:
 `00` |           ∞ |              ∞ |           ∞ |             ∞
 `01` |        4.1s |           7.2s |        4.1s |           38s
 `02` |        3.1s |           5.4s |        3.1s |           28s
 `03` |        2.6s |           4.6s |        2.6s |           24s
 `04` |        2.0s |           3.5s |        2.0s |           19s
 `05` |        1.5s |           2.6s |        1.5s |           14s
 `06` |        1.3s |           2.3s |        1.3s |           12s
 `07` |        1.0s |           1.8s |        1.0s |          9.4s
 `08` |       770ms |           1.3s |       770ms |          7.1s
 `09` |       640ms |           1.1s |       640ms |          5.9s
 `0A` |       510ms |          900ms |       510ms |          4.7s
 `0B` |       380ms |          670ms |       380ms |          3.5s
 `0C` |       320ms |          560ms |       320ms |          2.9s
 `0D` |       260ms |          450ms |       260ms |          2.4s
 `0E` |       190ms |          340ms |       190ms |          1.8s
 `0F` |       160ms |          280ms |       160ms |          1.5s
 `10` |       130ms |          220ms |       130ms |          1.2s
 `11` |        96ms |          170ms |        96ms |         880ms
 `12` |        80ms |          140ms |        80ms |         740ms
 `13` |        64ms |          110ms |        64ms |         590ms
 `14` |        48ms |           84ms |        48ms |         440ms
 `15` |        40ms |           70ms |        40ms |         370ms
 `16` |        32ms |           56ms |        32ms |         290ms
 `17` |        24ms |           42ms |        24ms |         220ms
 `18` |        20ms |           35ms |        20ms |         180ms
 `19` |        16ms |           28ms |        16ms |         150ms
 `1A` |        12ms |           21ms |        12ms |         110ms
 `1B` |        10ms |           18ms |        10ms |          92ms
 `1C` |         8ms |           14ms |         8ms |          74ms
 `1D` |         6ms |           11ms |         6ms |          55ms
 `1E` |         4ms |            7ms |         4ms |          37ms
 `1F` |         2ms |          3.5ms |         2ms |          18ms

reference: [Super Famicom Development Wiki](https://wiki.superfamicom.org/spc700-reference#dsp-voice-register:-gain-1156)

## noise frequencies

value |  freq. | value |    freq.
----: | -----: | ----: | -------:
`00`  |   0 Hz | `10`  |   500 Hz
`01`  |  16 Hz | `11`  |   667 Hz
`02`  |  21 Hz | `12`  |   800 Hz
`03`  |  25 Hz | `13`  |  1.0 KHz
`04`  |  31 Hz | `14`  |  1.3 KHz
`05`  |  42 Hz | `15`  |  1.6 KHz
`06`  |  50 Hz | `16`  |  2.0 KHz
`07`  |  63 Hz | `17`  |  2.7 KHz
`08`  |  83 Hz | `18`  |  3.2 KHz
`09`  | 100 Hz | `19`  |  4.0 KHz
`0A`  | 125 Hz | `1A`  |  5.3 KHz
`0B`  | 167 Hz | `1B`  |  6.4 KHz
`0C`  | 200 Hz | `1C`  |  8.0 KHz
`0D`  | 250 Hz | `1D`  | 10.7 KHz
`0E`  | 333 Hz | `1E`  |   16 KHz
`0F`  | 400 Hz | `1F`  |   32 KHz

reference: [Super Famicom Development Wiki](https://wiki.superfamicom.org/spc700-reference#dsp-register:-flg-1318)

## resources

- [SNES-format BRR samples](https://www.smwcentral.net/?p=stion&s=brrsamples) at SMW Central
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`# Super Nintendo Entertainment System (SNES) / Super Famicom`
WIP SNES support, part 1 2022-03-21 07:38:12 +00:00
lots of doc updates 2022-10-16 05:53:05 +00:00			`the successor to NES to compete with Genesis, packing superior graphics and sample-based audio.`
WIP SNES support, part 1 2022-03-21 07:38:12 +00:00
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`its Sony-developed audio system features a DSP chip, SPC700 CPU, and 64KB of dedicated SRAM used by both.`
lots of doc updates 2022-10-16 05:53:05 +00:00			`this whole system itself is pretty much a separate computer that the main CPU needs to upload its program and samples to.`
WIP SNES support, part 1 2022-03-21 07:38:12 +00:00
lots of doc updates 2022-10-16 05:53:05 +00:00			`Furnace communicates with the DSP directly and provides a full 64KB of memory. this memory might be reduced excessively on ROM export to make up for playback engine and pattern data. you can go to window > statistics to see how much memory your samples are using.`
WIP SNES support, part 1 2022-03-21 07:38:12 +00:00
lots of doc updates 2022-10-16 05:53:05 +00:00			`some notable features of the DSP are:`
doc finalization: systems 2023-09-10 06:44:29 +00:00			`- pitch modulation.`
lots of doc updates 2022-10-16 05:53:05 +00:00			`- a built in noise generator, useful for hi-hats, cymbals, rides, effects, among other things.`
			`- per-channel echo, which unfortunately eats up a lot of memory but can be used to save channels in songs.`
			`- an 8-tap FIR filter for the echo, which is basically a procedural low-pass filter that you can edit however you want.`
			`- sample loop, but the loop points have to be multiples of 16.`
			`- left/right channel invert for surround sound.`
			`- ADSR and gain envelope modes.`
			`- 7-bit volume per channel.`
			`- sample interpolation, which is basically a low-pass filter that gets affected by the pitch of the channel.`
Improve SNES documentation 2022-10-08 17:15:05 +00:00
doc finalization: systems 2023-09-10 06:44:29 +00:00			`Furnace also allows the SNES to use wavetables (and the wavetable synthesizer) in order to create more 'animated' sounds, using less memory than regular samples.`
WIP SNES support, part 1 2022-03-21 07:38:12 +00:00
only one header per doc file 2023-09-11 00:34:13 +00:00			`## effects`
WIP SNES support, part 1 2022-03-21 07:38:12 +00:00
Lots of little cleanup. Trying for more consistency and clarity, especially for quick reference. 2023-06-25 07:05:30 +00:00			- `10xx`: set waveform.
			- `11xx`: toggle noise mode.
			- `12xx`: toggle echo on this channel.
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			- `13xx`: toggle pitch modulation. frequency modulation by the previous channel's output. no effect on channel 1.
			- `14xy`: toggle inverting the left or right channels. `x` is left, `y` is right.
			- `15xx`: set envelope mode. see gain chart below for `1` through `5`.
			- `0`: ADSR mode.
			- `1`: gain (direct). volume holds at one level.
			- `2`: linear decrement. volume lowers by subtractions of 1/64.
			- `3`: exponential decrement. volume lowers by multiplications of 255/256.
			- `4`: linear increment. volume rises by additions of 1/64.
			- `5`: bent line (inverse log) increment. volume rises by additions of 1/64 until 3/4, then additions of 1/256.
Lots of little cleanup. Trying for more consistency and clarity, especially for quick reference. 2023-06-25 07:05:30 +00:00			- `16xx`: set gain. `00` to `7F` if direct, `00` to `1F` otherwise.
			- `18xx`: enable echo buffer.
			- `19xx`: set echo delay. range is `0` to `F`.
eliminate use of backslash in doc 2023-09-11 00:12:56 +00:00			- `1Axx`: set left echo channel volume.
			- `1Bxx`: set right echo channel volume.
			- `1Cxx`: set echo feedback.
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`- all of these are signed numbers.`
Lots of little cleanup. Trying for more consistency and clarity, especially for quick reference. 2023-06-25 07:05:30 +00:00			- `00` to `7F` for 0 to 127.
			- `80` to `FF` for -128 to -1.
eliminate use of backslash in doc 2023-09-11 00:12:56 +00:00			`- setting these to -128 is not recommended as it may cause echo output to overflow and therefore click.`
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			- `1Dxx`: set noise generator frequency. range is `00` to `1F`. see noise frequencies chart below.
eliminate use of backslash in doc 2023-09-11 00:12:56 +00:00			- `1Exx`: set left dry / global volume.
			- `1Fxx`: set right dry / global volume.
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`- these do not affect echo.`
eliminate use of backslash in doc 2023-09-11 00:12:56 +00:00			- `20xx`: set attack. range is `0` to `F`.
			- `21xx`: set decay. range is `0` to `7`.
			- `22xx`: set sustain. range is `0` to `7`.
			- `23xx`: set release. range is `00` to `1F`.
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`- these four are only used in ADSR envelope mode. see ADSR chart below.`
eliminate use of backslash in doc 2023-09-11 00:12:56 +00:00			- `3xyy`: set echo filter coefficient.
			- `x` is the coefficient from 0 to 7.
			- `yy` is the value (signed number).
			- `00` to `7F` for 0 to 127.
			- `80` to `FF` for -128 to -1.
note 2023-09-10 22:13:33 +00:00			`- note: be sure the sum of all coefficients is between -128 and 127. sums outside that may result in overflow and therefore clicking.`
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`- see [SnesLab](https://sneslab.net/wiki/FIR_Filter) for a full explanation and examples.`

only one header per doc file 2023-09-11 00:34:13 +00:00			`## info`
Documentation stuff! New page for the effect list, updates to chanOsc, and links to instrument types from every "system" page. 2023-08-04 16:11:53 +00:00
Teensy formatting change. None of these should be list items. It was a bad idea. 2023-08-04 16:38:05 +00:00			`this chip uses the [SNES](../4-instrument/snes.md) instrument editor.`

Removing excess quote marks. 2023-11-06 03:17:08 +00:00			when two channels are joined for pitch modulation, the channel bar will show `mod` on a bracket tying them together.
Documenting channel pair hints. 2023-11-03 03:32:21 +00:00
Docs for channel status indicators. 2023-11-01 17:25:26 +00:00			`## channel status`

fix the doc 2023-11-01 23:37:28 +00:00			`the following icons are displayed when channel status is enabled in the pattern view:`

			`- envelope/gain status:`
			`- ![direct gain, envelope off](status-SNES-gain-direct.png) direct gain`
			`- ![linear gain decrease](status-SNES-gain-dec-lin.png) linear gain decrease`
			`- ![logarithmic gain decrease](status-SNES-gain-dec-log.png) logarithmic gain decrease`
			`- ![linear gain increase](status-SNES-gain-inc-lin.png) linear gain increase`
			`- ![bent-line gain increase](status-SNES-gain-inc-bent.png) bent-line gain increase`
			`- ![envelope attack](status-SNES-env-A.png) envelope attack`
			`- ![envelope decay](status-SNES-env-D.png) envelope decay`
			`- ![envelope sustain](status-SNES-env-S.png) envelope sustain`
			`- ![envelope release](status-SNES-env-R.png) envelope release`
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00
document chip options 2024-07-06 19:52:07 +00:00			`## chip config`

			`the following options are available in the Chip Manager window:`

			`- Volume scale: scale volumes to prevent clipping/distortion.`
			`- Enable echo: enables the echo buffer.`
			`- Initial echo state: selects which channels will have echo applied.`
			`- Delay: sets echo length.`
			`- Feedback: sets how much of the echo output will be fed back into the buffer.`
			`- Echo volume: sets echo volume.`
			`- Echo filter: adjusts echo filter.`

SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00			`## ADSR`

			`\| attack \| 0→1 time \| decay \| 1→S time \| sustain \| ratio \| release \| S→0 time`
			`\| -----: \| -------: \| ----: \| -------: \| ------: \| :---: \| ------: \| -------:`
Trying again, no spaces this time. 2023-07-01 04:27:46 +00:00			\| `00` \| 4.1s \| `00` \| 1.2s \| `00` \| 1/8 \| `00` \| ∞
			\| `01` \| 2.5s \| `01` \| 740ms \| `01` \| 2/8 \| `01` \| 38s
			\| `02` \| 1.5s \| `02` \| 440ms \| `02` \| 3/8 \| `02` \| 28s
			\| `03` \| 1.0s \| `03` \| 290ms \| `03` \| 4/8 \| `03` \| 24s
			\| `04` \| 640ms \| `04` \| 180ms \| `04` \| 5/8 \| `04` \| 19s
			\| `05` \| 380ms \| `05` \| 110ms \| `05` \| 6/8 \| `05` \| 14s
			\| `06` \| 260ms \| `06` \| 74ms \| `06` \| 7/8 \| `06` \| 12s
			\| `07` \| 160ms \| `07` \| 37ms \| `07` \| 1 \| `07` \| 9.4s
			\| `08` \| 96ms \| \| \| \| \| `08` \| 7.1s
			\| `09` \| 64ms \| \| \| \| \| `09` \| 5.9s
			\| `0A` \| 40ms \| \| \| \| \| `0A` \| 4.7s
			\| `0B` \| 24ms \| \| \| \| \| `0B` \| 3.5s
			\| `0C` \| 16ms \| \| \| \| \| `0C` \| 2.9s
			\| `0D` \| 10ms \| \| \| \| \| `0D` \| 2.4s
			\| `0E` \| 6ms \| \| \| \| \| `0E` \| 1.8s
			\| `0F` \| 0ms \| \| \| \| \| `0F` \| 1.5s
			\| \| \| \| \| \| \| `10` \| 1.2s
			\| \| \| \| \| \| \| `11` \| 880ms
			\| \| \| \| \| \| \| `12` \| 740ms
			\| \| \| \| \| \| \| `13` \| 590ms
			\| \| \| \| \| \| \| `14` \| 440ms
			\| \| \| \| \| \| \| `15` \| 370ms
			\| \| \| \| \| \| \| `16` \| 290ms
			\| \| \| \| \| \| \| `17` \| 220ms
			\| \| \| \| \| \| \| `18` \| 180ms
			\| \| \| \| \| \| \| `19` \| 150ms
			\| \| \| \| \| \| \| `1A` \| 110ms
			\| \| \| \| \| \| \| `1B` \| 92ms
			\| \| \| \| \| \| \| `1C` \| 74ms
			\| \| \| \| \| \| \| `1D` \| 55ms
			\| \| \| \| \| \| \| `1E` \| 37ms
			\| \| \| \| \| \| \| `1F` \| 18ms
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00
			`reference: [Super Famicom Development Wiki](https://wiki.superfamicom.org/spc700-reference#dsp-voice-register:-adsr-1097)`

			`## gain`

			`value \| linear inc. \| bent line inc. \| linear dec. \| exponent dec.`
			`----: \| ----------: \| -------------: \| ----------: \| ------------:`
			`00` \| ∞ \| ∞ \| ∞ \| ∞
Trying again, no spaces this time. 2023-07-01 04:27:46 +00:00			`01` \| 4.1s \| 7.2s \| 4.1s \| 38s
			`02` \| 3.1s \| 5.4s \| 3.1s \| 28s
			`03` \| 2.6s \| 4.6s \| 2.6s \| 24s
			`04` \| 2.0s \| 3.5s \| 2.0s \| 19s
			`05` \| 1.5s \| 2.6s \| 1.5s \| 14s
			`06` \| 1.3s \| 2.3s \| 1.3s \| 12s
			`07` \| 1.0s \| 1.8s \| 1.0s \| 9.4s
			`08` \| 770ms \| 1.3s \| 770ms \| 7.1s
			`09` \| 640ms \| 1.1s \| 640ms \| 5.9s
			`0A` \| 510ms \| 900ms \| 510ms \| 4.7s
			`0B` \| 380ms \| 670ms \| 380ms \| 3.5s
			`0C` \| 320ms \| 560ms \| 320ms \| 2.9s
			`0D` \| 260ms \| 450ms \| 260ms \| 2.4s
			`0E` \| 190ms \| 340ms \| 190ms \| 1.8s
			`0F` \| 160ms \| 280ms \| 160ms \| 1.5s
			`10` \| 130ms \| 220ms \| 130ms \| 1.2s
			`11` \| 96ms \| 170ms \| 96ms \| 880ms
			`12` \| 80ms \| 140ms \| 80ms \| 740ms
			`13` \| 64ms \| 110ms \| 64ms \| 590ms
			`14` \| 48ms \| 84ms \| 48ms \| 440ms
			`15` \| 40ms \| 70ms \| 40ms \| 370ms
			`16` \| 32ms \| 56ms \| 32ms \| 290ms
			`17` \| 24ms \| 42ms \| 24ms \| 220ms
			`18` \| 20ms \| 35ms \| 20ms \| 180ms
			`19` \| 16ms \| 28ms \| 16ms \| 150ms
			`1A` \| 12ms \| 21ms \| 12ms \| 110ms
			`1B` \| 10ms \| 18ms \| 10ms \| 92ms
			`1C` \| 8ms \| 14ms \| 8ms \| 74ms
			`1D` \| 6ms \| 11ms \| 6ms \| 55ms
			`1E` \| 4ms \| 7ms \| 4ms \| 37ms
			`1F` \| 2ms \| 3.5ms \| 2ms \| 18ms
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00
			`reference: [Super Famicom Development Wiki](https://wiki.superfamicom.org/spc700-reference#dsp-voice-register:-gain-1156)`

			`## noise frequencies`

			`value \| freq. \| value \| freq.`
			`----: \| -----: \| ----: \| -------:`
			`00` \| 0 Hz \| `10` \| 500 Hz
			`01` \| 16 Hz \| `11` \| 667 Hz
			`02` \| 21 Hz \| `12` \| 800 Hz
			`03` \| 25 Hz \| `13` \| 1.0 KHz
			`04` \| 31 Hz \| `14` \| 1.3 KHz
			`05` \| 42 Hz \| `15` \| 1.6 KHz
			`06` \| 50 Hz \| `16` \| 2.0 KHz
			`07` \| 63 Hz \| `17` \| 2.7 KHz
			`08` \| 83 Hz \| `18` \| 3.2 KHz
			`09` \| 100 Hz \| `19` \| 4.0 KHz
			`0A` \| 125 Hz \| `1A` \| 5.3 KHz
			`0B` \| 167 Hz \| `1B` \| 6.4 KHz
			`0C` \| 200 Hz \| `1C` \| 8.0 KHz
			`0D` \| 250 Hz \| `1D` \| 10.7 KHz
			`0E` \| 333 Hz \| `1E` \| 16 KHz
			`0F` \| 400 Hz \| `1F` \| 32 KHz

			`reference: [Super Famicom Development Wiki](https://wiki.superfamicom.org/spc700-reference#dsp-register:-flg-1318)`

only one header per doc file 2023-09-11 00:34:13 +00:00			`## resources`
SNES docs (and other tweaks) 2023-06-27 21:06:23 +00:00
Abbreviating the abbreviations. Shortening to `msec` and `sec` to `ms` and `s` respectively. 2023-07-01 04:23:55 +00:00			`- [SNES-format BRR samples](https://www.smwcentral.net/?p=stion&s=brrsamples) at SMW Central`