- Allowed notes are C-1..D-6, Note Cut (rest note)

- Only Volume, Arpeggio, and Pitch sequences (no Pitch for noise

channel) supported

- All instruments should have a volume envelope assigned

- Only the loop part of sequence is supported, release part is not supported

- Pitch envelope accumulate the offset at conversion time only, thus

it can't go further -64..63, and can't accumulate the offset with loop

- Only first step of Duty envelope for pulse and noise channels is used,

there is no Duty sequence

- 64 instruments max

- No volume column support

- Tempo is set with the global setting, speed can be changed with effect

Fxx (1..21)

- Bxx effect for looping without an intro, does not support forward

references

- D00 effect to cut patterns early

- No effects other than listed above are supported

- Up to 17 sub songs in a file, they will share instruments and pattern

data