The resulting output of the bio-amplifier is monitored on a cathode ray or digital oscilloscope.
The company's initial focus was on test instrumentation and it brought the world's first digital oscilloscope to South Africa in the same year.
A disadvantage of digital oscilloscopes is the limited refresh rate of the screen.
For a digital oscilloscope, the screen looks exactly the same for any signal rate which exceeds the screen's refresh rate.
These are now called "analog" oscilloscopes to distinguish them from the "digital" oscilloscopes that became common in the 1990s and 2000s.
Many digital oscilloscopes use flat panel displays similar to those made in high volumes for computers and television displays.
Even if the magnitude of the variations in power consumption are small, standard digital oscilloscopes can easily show the data-induced variations.
Starting in the 1980s, digital oscilloscopes became prevalent.
A digital oscilloscope and waveform monitor were stacked over one of the computers.
Each waveform was taken using a digital oscilloscope set to trigger when the voltage across the inductor dipped below zero.