[Hewitson]

Originally Posted by 8bitbubsy

Actually yeah, it's related to sample swapping but also a replayer bug. I found the issue after looking around for a bit.

The replayer in the VF cracktro has a design error with restarting the song after the last position was played. Instead of setting the current pattern to the first entry in the "order table", it sets it to 0. This is wrong. In the song, position 0 has pattern 1, position 1 has pattern 0 (according to the table), and so on.

Pattern 0 (pos 1) starts with a portamento on the lead channel, so after the song wraps it goes from sample 7 to sample 6 with the portamento. The combination of sample swapping and portamento can give really strange results, I don't fully understand how it works to be honest. The song wraps fine in ProTracker (and my clone).

Interesting. Thanks for the detailed explanation!