Command 0x15: Set echo parameters

Sets the echo feedback and volume, and enables echo.

Syntax

0x15, sbyte feedback, sbyte left, sbyte right

Parameters

Parameter	Type	Contents
feedback	sbyte	Echo feedback (DSP EFB)
left	sbyte	Left echo volume (EVOL)
right	sbyte	Right echo volume (EVOL)

Remarks

Immediately sets the DSP EFB and EVOL, and saves the echo volume to $0232, $0233.
At the same time, it writes 0 to the DSP FLG register, allowing writes to the echo buffer. From then on, echo writes remain allowed even when the noise clock is set (command 0x19).

To apply echo to each channel, use command 0x16 separately.

This command takes no time to process, and the following event is read within the same tick.

Note

Since 0 is written to the FLG register, the noise clock also becomes 0. If you use noise, execute command 0x19 after this command.
The echo delay is set with command 0x1F. Command 0x1F disables echo writes, so execute it before this command.