older disk-based cmix instruments
superceded by rtsetoutput and and rtsetinput.
Here is the original documentation:
setnote() positions the disk pointers on the previously opened file number to compute (duration * sampling rate). If starttime is a negative value its absolute value is equal to the number of samples per channel to skip on the file before reading or writing, and if duration is negative its value equals the number of samples per channel to compute. If setnote() seeks beyond the current end of the file empty space will be created between that point and the position it points to. This will appear to all software as 0’s but will not actually hog up any real disk space. The D-A conversion program will play silence during that point.
ADDOUT, WIPEOUT, LAYOUT, endnote
If something is wrong setnote() will kill the run by itself.