V9958 YJK (YUV) mode

Some time ago we introduced a tiny tool called ppmview.prg in our collection of tools and progs for our Steckschwein. The ppmview.prg, as the name already tells, is able to load an image in ppm (Portable BitMap) format with a maximum size of 256x212px and displays it on the screen. The first version of ppmview was released in 2018 and since then we just use the SCREEN 8 (MSX) also known as graphic mode 7 (RGB).