The author notes that circles don't draw well due to mouse polling, but I wonder if this isn't a limit of the emulator running on Windows. I remember Deluxe Paint III on the Amiga drawing freehand circles very well, whereas MS Paint on Windows 95, quickly drawn circles ended up looking like polyhedrons due to infrequent polling.
There's a neat modern DPaint clone called PyDPainter (https://github.com/mriale/PyDPainter). It has various advantages, such as support for modern graphics formats like PNG.
There's a neat modern DPaint clone called PyDPainter (https://github.com/mriale/PyDPainter). It has various advantages, such as support for modern graphics formats like PNG.