2024-04-14 11:15:23 -04:00
|
|
|
# 5E01
|
|
|
|
|
|
|
|
|
|
a fantasy sound chip created by Euly, based on the Ricoh 2A03, with some improvements:
|
|
|
|
|
|
|
|
|
|
- a 37.5% duty cycle,
|
|
|
|
|
- 32 noise pitches instead of 16, and
|
|
|
|
|
- triangle channel becomes a wave channel, with four available waveforms: triangle, saw, sine and square.
|
|
|
|
|
|
|
|
|
|
## effects
|
|
|
|
|
|
|
|
|
|
- `11xx`: **write to delta modulation counter.** range is `00` to `7F`.
|
|
|
|
|
- this may be used to attenuate the triangle and noise channels; at `7F`, they will be at about 57% volume.
|
|
|
|
|
- will not work if a sample is playing.
|
|
|
|
|
- `12xx`: **set duty cycle/noise mode/waveform of channel.**
|
|
|
|
|
- may be `0` to `3` for the pulse channels:
|
|
|
|
|
- `0`: 12.5%
|
|
|
|
|
- `1`: 25%
|
|
|
|
|
- `2`: 37.5%
|
|
|
|
|
- `3`: 50%
|
|
|
|
|
- may be `0` or `1` for the noise channel:
|
|
|
|
|
- `0`: long (15-bit LFSR, 32767-step)
|
|
|
|
|
- `1`: short (9-bit LFSR, 93-step)
|
|
|
|
|
- may be `0` to `3` for the wave channel:
|
|
|
|
|
- `0`: triangle
|
|
|
|
|
- `1`: saw
|
|
|
|
|
- `2`: square
|
|
|
|
|
- `3`: sine
|
|
|
|
|
- `13xy`: **setup sweep up.**
|
|
|
|
|
- `x` is the time.
|
|
|
|
|
- `y` is the shift.
|
|
|
|
|
- set to `0` to disable it.
|
|
|
|
|
- `14xy`: **setup sweep down.**
|
|
|
|
|
- `x` is the time.
|
|
|
|
|
- `y` is the shift.
|
|
|
|
|
- set to `0` to disable it.
|
|
|
|
|
- `15xx`: **set envelope mode.**
|
|
|
|
|
- `0`: envelope + length counter. volume represents envelope duration.
|
|
|
|
|
- `1`: length counter. volume represents output volume.
|
|
|
|
|
- `2`: looping envelope. volume represents envelope duration.
|
|
|
|
|
- `3`: constant volume. default value. volume represents output volume.
|
|
|
|
|
- pulse and noise channels only.
|
|
|
|
|
- you may need to apply a phase reset (using the macro) to make the envelope effective.
|
|
|
|
|
- `16xx`: **set length counter.**
|
|
|
|
|
- see [NES](nes.md) for more information.
|
|
|
|
|
- this will trigger phase reset.
|
|
|
|
|
- `17xx`: **set frame counter mode.**
|
|
|
|
|
- `0`: 4-step.
|
|
|
|
|
- `1`: 5-step.
|
|
|
|
|
- `18xx`: **set PCM channel mode.**
|
|
|
|
|
- `00`: PCM (software).
|
|
|
|
|
- `01`: DPCM (hardware).
|
|
|
|
|
- when in DPCM mode, samples will sound muffled (due to its nature), availables pitches are limited, and loop point is ignored.
|
|
|
|
|
- `19xx`: **set triangle linear counter.**
|
|
|
|
|
- `00` to `7F` set the counter.
|
|
|
|
|
- `80` and higher halt it.
|
|
|
|
|
- `20xx`: **set DPCM frequency.**
|
|
|
|
|
- only works in DPCM mode.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
## info
|
|
|
|
|
|
|
|
|
|
this chip uses the [NES](../4-instrument/nes.md) instrument editor.
|
2024-07-06 15:52:07 -04:00
|
|
|
|
|
|
|
|
## chip config
|
|
|
|
|
|
|
|
|
|
the following options are available in the Chip Manager window:
|
|
|
|
|
|
|
|
|
|
- **Clock rate**: sets the rate at which the chip will run.
|
|
|
|
|
- **DPCM channel mode**: allows you to set which mode to use for the DPCM channel.
|
|
|
|
|
- DPCM: the default mode, playing 1-bit DPCM samples as supported by the hardware.
|
|
|
|
|
- PCM: this mode provides crispier samples by writing the delta counter directly. uses a lot of CPU time in console.
|
