8 bit vcdo

A while back I made a "deconstructed sequencer" out of logic chips. Its funny to go back and read that post because the post says the sequencer is "awaiting repairs", and that is definitely still the case.

This weekend I spent quite a bit of time working on re-writing my delay table generator. 

The 8 bit VCDO generates an audio signal by spitting out each sample of a waveform, one at a time. I do not use a timer on the chip to achieve this (maybe I should have). Instead, I manually track how many processor cycles take place every time I go through the main loop. Depending on what pitch I am trying to achieve, I delay a specified number of processor cycles (fetched from a lookup table) before moving on with the loop. 

Tonight I finally got my first prototype filter mocked up for the 8 bit VCO. Okay, technically that's not true, I've made four separate output filters so far. But they've all had problems one way or another.

The first one, a passive filter, was just too rough. Second one was alright but I lost my paper with the component values on it. Easier to just design it all over again.

Last month I participated in the Minneapolis St. Paul Mini Maker Faire! This was my third year exhibiting. (I have to dig through the archives to find pictures of my previous years exhibits and post those at some point).

This year, after the faire was over, I remembered to do a little video that demonstrated my "analog" synthesizer. Here it is: