A voltage-doubler circuit detects the 22-Hz portion, producing a pulse stream in which constant-voltage pulses having amplitudes of 0.6 to 1.2V replace the 22-Hz bursts. Decoding this bit stream into ...

Figure 4 The Shannon decoder principle applied to extending 8-bit DAC resolution. U1 is an 8-bit, voltage output, resistor-string type DAC (e.g., TLV5624) controlled by a standard SPI serial interface ...

The total circuit is incredibly compact for a complete CPU, using just 33 chips. This includes 64 KB of flash to store programs as well as a 555 timer to generate a clock signal.

My manager studied electrical engineering in Columbia in the early 90’s, and every student had to build an 8-bit TTL CPU. I wish modern American universities provided that depth in their curriculum.