BeetBoop

Hello! This is BeetBoop, my entry for the CatJam 2026!

This is a small tracker inspired by LSDj, written in Uxntal, that can run in a Varvara emulator that supports audio and files.

This is my first big Uxntal project! It is pretty rough and still misses lots of QoL improvements, but it works! Load the demo song by typing the name demo.bbp in the file name field and select Load then press Enter for a quick demo! Unfortunately you cannot save with the web version.

Use the arrow keys to navigate, and the tab key switch views (also shift-tab).

In the first view, you can change the tempo, file name, save and load a file. Use + and − to change the tempo, and almost all values.

A song contains one column for each channel and many rows that will be read sequentially. At the crossing of each row and column you can set the number of a pattern. You can input the hexadecimal number of a pattern directly. Use tab to go to the pattern view of the selected pattern.

Each row contains a note. While the first column is selected, press the name of the note, CDEFGAB, to put a note, backspace to remove it. The + and − key change octave. The S key will sharpen the note. In the second column, you can set the instrument with + and −. Use tab to switch to the instrument view. The last column contains the volume. Use + and − to change the volume, < and > to pan left or right.

In the instrument view, you can change the name of the instrument, choose a waveform with + or −, and change the ADSR envelope with + or − or by typing an hexadecimal digit.

Press space to play your song! If you're in the pattern view, pressing space will play the pattern on repeat. The rhythm is a little uneven on JavaScript unfortunately.

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Some Technical aspects

BeetBoop will advance the timer and check if it has to play notes at each frame, thus the resolution is only 60Hz, the framerate of a Varvara machine, which explains why the tempo resolution is so coarse.

BeetBoop uses the audio devices of Varvara in the most simple way. There is just a buffer for noise that is updated at each frame. While it is possible to synthesize audio in a more complex way, it will be CPU intensive, which defeats the one of BeetBoop's purposes below.

BeetBoop aims to help compose music that can be used during a game written in Uxntal. The playing routines is very simple and can be included in a game to add music to it! It is not ready yet but that's the goal. The game has to be efficient because if the framerate is too low, the music will slow down!

I have found that programs for Varvara running in a browser don't have any sound, but I wanted to have sound for my little program, so I hacked it into uxn5, not in the best way as you'll notice sooner than later, but I'm gonna refine that somewhat in the future and contribute back the changes to uxn5 if they are deemed worthy.

By the way there are a few dragons hidden in the game, if you call them maybe they'll show themselves!