A better eight-stage, one-bit waveform

I have meant to post this for a while, and a little email exchange over the weekend reminded me that i finally should. Here is a 'better' version of the eight-stage, one-bit custom waveform generator found on the fun with sea-moss page.

The circuit now has eight pull-down resistors which should mean for a more faithful reproduction of what the DIP switch is representing in terms of the waveform. R2 to R9 should be between 4kΩ and 20kΩ. In the breadboard example i have used 20kΩ. The values of R1 and C1 set the frequency of the waveform.