An Amiga bootblock for Under Construction 2016, ranked 1st place in the Combined Oldskool compo.

The snotty name is derived from “rotzoomer”, an effect that hadn’t been done in a bootblock before, as far as I can tell. Thanks to Blueberry’s Shrinkler compression, I was able to cram a lot of data into the 1 kilobyte of the bootblock, even allowing the Amiga to boot normally after the intro: 6,020 bytes of code and over 300k of (repetitive, mostly empty) data! In the final version, there even would have been 82 bytes left for a bigger logo.

Also, bitch/AttentionWhore provided an excellent mini-tune that really pushes this production forward! The crappy minimalistic samples are hard-coded by me, though. :)

Tech

The texture consists of 64×64 rgb values generated using a plasma formula and shifted a bit for each color channel:

To display the rotated/zoomed texture, a 5-bit display with a single repeated line of 32 colors is set up, with the Copper updating all colors every 4 lines. The ATW logo is a little sprite.

The instruments are rendered into four 64 KB wave buffers, one for each channel.

Each buffer represents a pattern of music data (i.e. 64 rows in ProTracker), and all the buffers are played in an endless loop. The samples are rendered directly into those buffers (with the square wave rendered in different pitches).

Links