Yes, you need assembler. It’s an interrupt timing trick. The VIC is able to show sprites in the border, but the frame is just hiding them, so the sprites can slide behind it. It’s connected to scan lines displayed by the VIC. For lower/upper borders it’s quite simple: Programm an interrupt, synced to start at … Read more
Firstly only sprites can be displayed in the border area or a repeating 8 bit pattern (8 pixels wide) which is read from the last byte of the video bank, usually $3fff. Note you can only see these sprites or 8 bit pattern when you trick the VIC chip into “not displaying” the borders. See … Read more
Emulation is a multi-faceted area. Here are the basic ideas and functional components. I’m going to break it into pieces and then fill in the details via edits. Many of the things I’m going to describe will require knowledge of the inner workings of processors — assembly knowledge is necessary. If I’m a bit too … Read more