Tag Archives: Assembly

Demo Code #1 – Vector Graphics

L Break Into Program, 0:1

I’m currently working on a vector graphics library; this will eventually include fast implementations of line, circle and triangle rendering. There will be options to render on the standard Spectrum screen (with it’s horrid layout) and to a more sensibly laid out offscreen bitmap. I’m also going to add filled circle and triangle with optional texture shading (an 8×8 graphic). I’ve just reworked a version of Bresenhams Incremental Line Algorithm in Z80, working in one …

Z80 Opcodes

L Break Into Program, 0:1

I’ve just started adding lists of Z80 opcodes onto the site. I’m hoping to expand this eventually to include a brief explanation along with the T states and Machine Cycles to execute each command. It also includes what we used to call the “undocumented instruction set”; ironically these are now probably as documented as the official Z80 instructions. Here are the lists in all their glory! Enjoy.

And so it begins… Again…

L Break Into Program, 0:1

Well, I’ve finally dusted off my Z80 programming skills and after a little refresher course with the University of Internet I’ve developed this sprite demo. Most of the concepts here are not new; they are how I wrote games back in the day. The sprite routine is basic; it does not mask, but it is using pre-shifted sprites and running within a vertical interrupt routine. The red border, by the way, indicates how much raster …