In case the Dutchtronix oscilloscope clock kit didn’t mix enough modalities then consider this an alternative. -

Digital clock circuit is based on AVR Attiny2313 microcontroller clocked at 4Mhz. Oscilloscope pattern is generated by using four microcontroller pins as DAC output.

So in review – we go from the our linear/analog perception of time, represent that digitally, convert that numerical value to analog voltage levels, so it may be represented yet again digitally. Yes, of course you could use a digital oscilloscope – but that may just disrupt the fabric of reality. – Link

Related:

AVR Oscilloscope Clock – Link

AVR Scope terminal – Oscilloscope terminal! – Link