Had some tough days figuring out the best concept for XY retractions.

I first tried a parallel ringbuffer with pure step and dir bits. Wasn't to happy with it and changed it to a position ringbuffer. But it was still not fully integrated.

Changed it again and now it is a pure ringbuffer that takes position instructions and syncs the position.

The motion can run up and down the  positions stored in the history buffer.

Homing works and the GCode simulation runs the G Logo file too.

The "G" created about 250 Lines. The history buffer is set to 1024 lines but this could be increased to for example 4096.

Lots of room for some tiny retractions.

In this video I jogged XYZ and then just let the history buffer walk back and forth.