Type help vgm_rec
for information about the command syntax.
Now I successfully recorded my scc song by using command "vgm_rec start psg scc",thanks.
But there's another question that the vgm recorded by myself seems to have some wrong tunes and pitches at the beginning of the song.And also if possible I'd like to ask how to controll vgm's speed ,how to edit a vgm file.But these things seems out of topic.Maybe I can ask these questions on Vgmrips?
Don't know if you need this answer anymore, but you might have to start recording before loading the tracker. If the tracker sends data to the SCC chip when started or loading the track for example, and you start recording after that, the VGM file won't contain those first instructions which might set up important things. You can manipulate VGM files using the tools that exist for that. Not sure if slow playback is possible though... I was wondering that myself, for playing along with tunes...