Sega PSG instrument editor

the instrument editor for Sega PSG, SMS, and other TI SN76489 derivatives consists of these macros:

• Volume: volume sequence.
• Arpeggio: pitch sequence.
• Duty: noise mode.
• 0: short noise; preset frequencies.
• 1: long noise; preset frequencies.
• 2: short noise; use channel 3 for frequency.
• 3: long noise; use channel 3 for frequency.
• Panning: output for left and right channels.
• only on Game Gear!
• Pitch: fine pitch.
• Phase Reset: trigger restart of noise only.