This release:
- resolves incorrect placement of data within a floppy disk track, potentially overwriting unrelated data, when any machine wrote two or more discontinuous regions during a single rotation;
- corrects video output of the Apple II, Vic-20 and Atari 2600 for the OpenGL targets, i.e. SDL and Qt;
- removes a half-second time skip at startup for all machines in Qt; and
- improves and possibly entirely-resolves issues with audio output under Qt.
All credit goes to @apenney for discovering, diagnosing and suggesting work on all of these. I can't guarantee I've yet succeeded in resolving all of his discoveries. Thanks!