Robert Willie (aka Hydrophilic) created Basic Mandelbrot program for VDC and Basic 7.80.
I modified it to use for VIC-IIe, VIC-II, TED, - so also Commodore VIC screen, Commodore 64, Commodore Plus/4 (and 16 or 116).
It was tested and compared. For C64 is used Basic 3.5.
I could test only Commodore 128 (both VDC and VIC-IIe) with or without SuperCPU, C64 mode and only emulator of Plus/4.
So, I created blog at cbmandelbrot.blogspot.sk/
If you want to help testing, look at and reply to comments.