Not so fast, ProTracker!

While testing my Coppenheimer update (still in progress), I loaded up ProTracker for testing. I started wondering how it paints the pattern data at the bottom of the screen (the song “contents”). Is it double-buffered? How fast can it redraw everything? (I know from experience that plotting little 8×8 characters with the CPU can get really slow – heck, it’s even slow in the browser without…