SAA1099: swap left channels

[Stefan Drissen]

Visually in the tracker view, the channels are laid out as:

1 2
4 3

So 1 and 4 are stereo left and 2 and 3 are stereo right, on which SAA1099 channel they are played (2 or 5) is irrelevant for audio purposes. However, thanks to the advent of oscilloscope videos, the channel does bother me. The oscilloscope videos show the SAA1099 output as:

2 left | right 2
5 left | right 5

Unfortunately mod channel 1 is sent to SAA channel 5 left and mod channel 4 is sent to SAA channel 2 left.

So while in the tracker view you see channel 1 (top left) doing drums, on the oscilloscope video you see the drums on 5 left (ie bottom left).