With a basic configuration (only EXOS 2.1, IS-BASIC and epfileio.rom, with 128 KB RAM), it works other than the cursor being drawn under the upper rows of icons (the lower 2-color ones do not have this problem). Using another configuration (EXOS 2.32 with 640 KB RAM and many ROMs), it was also invisible on the paint area at first after starting the program, but after moving the cursor to the icons and back, it became visible. I tested Paintobox 2.1R from ep128.hu.