Time to start getting familiar with using the zero page and use an interrupt for some simple effects. I decided to create a basic colour cycle effect that updates the colour map, shifting the character colours in a direction. Back in the day, I couldn’t get my head around how to actually achieve this via assembly language, but I’ve had a lot of experience in programming since then, so have a much better idea of how to achieve the effect.
A simple effect I remember seeing in many intros & demos was what I always called a “Widescreen” effect. This is where the top and bottom borders extended all the way to the edge of the screen. It gives the impression of parts of the side border being removed. There are methods for actually removing both the top and bottom borders, but that’s more complicated and something I will look at in the future. For now, I will look at using the raster bar to toggle the screen and border colours at specific scan lines to give the impression of a wide screen display.