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This command plays a tone derived from the parameter. The tone is played indefinitely until the rMP3 receives either the Play Tone command again with no parameter, or the Stop command. If a file is being played when the Play Tone command is received, playback will resume if the Play Tone command is received with no parameter.

Note: Tones are generated using the VS10xx decoder's “Sine Test”. The range and quantization of frequencies are pretty limited. For reference, here is an entire table of frequencies.

PC T [tone]

• tone is a value between 0 and 255.

  • To calculate the tone value:

    • Tone Frequency = Base Frequency * d/128

      • This means that there can be more than one combination of Base Frequency and d for a Tone Frequency.

    • tone = Base Frequency Index + d

    • d is the divider value (1 → 31), which will give a range of divider fractions (1/128 → 31/128). A divider value of 0 will produce no sound.

    • Base Frequency Index Table:

      	Base Frequency Index
      Base Frequency	Hexadecimal	Decimal
      44100 Hz	0x00	0
      48000 Hz	0x20	32
      32000 Hz	0x40	64
      22050 Hz	0x60	96
      24000 Hz	0x80	128
      16000 Hz	0xA0	160
      11025 Hz	0xC0	192
      12000 Hz	0xE0	224

    • Example:

      • Base Frequency = 48000 Hz, therefore Base Frequency Index = 32.

      • d = 16.

      • Tone Frequency = 48000 * 16/128 = 6000 Hz.

      • tone = 32 + 16 = 48

        • PC T 48

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