My Dynasty 200 DX offers Advanced squarewave, Soft squarewave and Sine wave with square transitions. Miller's Selecting a TIG Welder Q&A says that Squarewave is
Squarewave technology shortens the switching time between EN and EP so that the welding machine has sufficient "push" to drive the arc through the zero crossing and then re-establish the arc in the opposite polarity.
and that Advanced Squarewave
Advanced squarewave technology switches the weld polarity thousands of times faster than a conventional squarewave machine, dramatically improving arc starts and arc stability. It also permits more precise control over the weld puddle, bead width and penetration by adjusting output frequency and extending balance control.
Looking at the diagrams on page 6 of the TIG Buyers Guide

Do any of these waveforms look like the original Squarewave? If not, does anyone have a picture of what the original Squarewave looked like?