Topic: utz' beeper engine releases

Should've done this much earlier, I guess, but anyway: This will be where I announce my new engines from now on, instead of spamming the board with a new thread every time.

So, here we go, first new Speccy beeper engine of 2021. Basically this one is just wrapping up my recent experiments with PD synthesis. Might still tweak things later on, but for a simple proof-of-concept it's good enough as is methinks. No converter for now, though of course it'll be available in Bintracker sooner or later.


Aczidbox is a 1-bit sound engine for the ZX Spectrum beeper. It implements a simplified version of Phase Distortion Synthesis, as introduced by the Casio CZ range of synthesizers.

The two tone channels each feature a 16-bit base oscillator and a LFO-controlled 12-bit resonant oscillator. Channels each use 7 bits of volume information internally, which are reduced to 4 bits for the final mix.

3 different configurable click drum modes are available: synthesized kicks, synthesized noise, and PWM sample playback. Drums interrupt tone playback.

The core synthesis runs at 7812 Hz (double 224 cycle loop).

The source code is available on github, as usual.

Post's attachments

aczidbox-demo.tap 5.02 kb, 10 downloads since 2021-01-07 

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Re: utz' beeper engine releases

Amazing as always utz smile

Re: utz' beeper engine releases

ud - Ultimate Drum Synth

Added one to the collection of reusable click drum routines. This one can mix tone slides (kick/tom) and noise. Pitch and volume control for everything. Unlike the "kick" routine, the kick synth in ud uses only exponential pitch decay, but the decay speed can be controlled. 16-bit tempo control, because why not.

The source code can be found in the CLICK_DRUMS directory on my 1-bit engine github repo.

Post's attachments

test.tap 343 b, 8 downloads since 2021-01-10 

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Re: utz' beeper engine releases

Hi utz

Just tried the aczidbox tune again. Amazing. Notice it doesn't respond to keypress ?
A friend has nearly finished his space shooter game and this would be a great intro tune if the keypress was enabled.


Re: utz' beeper engine releases

Lol, was too lazy to add a keyhandler, cause I thought nobody would use this anyway yikes
Pushed an updated version with keyhandling to github. Source is for Pasmo assembler, btw.

Re: utz' beeper engine releases

very impressive as usual!

I want to dive into 1-bit music again!