furnace/doc/7-systems/gba.md

Game Boy Advance

a portable video game console from Nintendo, succeeding the Game Boy.

it adds two stereo sample audio channels which can be used directly ("DMA", left/right) or used in a software mixing driver (most games do this) in order to have multiple voices.

effects

• 10xx: change wave.

Game Boy Advance (MinMod)

this is the software mixing driver available in Furnace. it is written by Natt Akuma. it features echo and up to 16 voices.

• 10xx: change wave.

• 11xy: configure echo.

  • this effect is kinda odd. here's how to use it:
    • create an empty instrument and put a very high note of it in channel 1.
    • put 110x in the effect column.
    • set volume column to set feedback.
    • don't use the channel for anything else.

• 12xy: toggle invert.

  • x left channel.
  • y right channel.

info

this chip uses the GBA DMA and GBA MinMod instrument editors.

chip config

the following options are available in the Chip Manager window:

• DAC bit depth: sets the bit depth.

these options are available when using MinMod:

• Volume scale: scale volumes to prevent clipping/distortion.
• Mix buffers: sets how many mix buffers will be stored in memory. higher values result in longer echo.
• Channel limit: sets the number of channels that will be available. higher values use more CPU.
• Sample rate: sets the mixing rate. higher values use more CPU.