A little while back I put up a small tutorial on making a 1×1 text scroller. This tutorial builds on that foundation and becomes a dynamic 4×4 scroller. Why dynamic? I use this term since it builds each 4×4 character as needed, based on a character from a 1×1 font set. I achieve this by using a matrix of 16 character “patterns” that make up all possible 4×4 bit combinations. This is handy in situations where you’re pressed for memory in your intro and can achieve a 4×4 version of the 1×1 font for only an extra 128 bytes in font data.
While attending the Syntax demo scene party recently, I decided to look at an effect I had not yet tried but was keen to better understand. I decided it would be FLD – Flexible Line Distance. This effect allows you to move blocks of data vertically on the screen with little processing required. Because minimal processing is needed to move huge lumps of data, it’s great for sliding bitmaps images / logos up and down the screen without having to copy any of the data each frame.
I’ve created a few single file intros now and have been interested in expanding out to something bigger. There are some pretty awesome one file demos around that I’d like to work my way towards, but I’d also like to be able to have the option to load content off disk. From some initial research, I found there were a handful of common loaders around that people used. My first thought was to dive in and learn to use one. Before I do that however, I wanted to take a step back and start from the start to gain a much deeper understanding of how loaders evolved. Many of the demos I grew up with in the late 80’s and early 90’s contained multiple parts that were loaded separately off disk (or tape) and I felt this would be a good starting point.
What’s this? A new release and not a demo party in sight? I wanted to maintain some momentum this year with the goal of entering another demo into the next Syntax scene party. To make that possible, I figure it’s wise to keep active on the C64 and do a few smaller releases over the year. So with that, I present to you a small intro – 3172 – which is heavily influenced by old skool intros and cracktros.
A very important component of any demo is having a kick arse SID chip track backing it. That means, we need to be able to play a track while performing some mastery of the raster bar. It was something I was dreading looking at, but turned out to be a very straight forward thing and only ended up taking about 10 minutes to get working.