uch as “these segments are horizontal” or “I am drawing an arc”. A constraint solver translated sloppy light pen gestures into precise coordinates to honor the declarations. Fun tech note: constraints were declared by throwing toggle switches.</p>
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<p style="direction:ltr;">Age 15 wrote biggest app for SIMON: 8 feet of paper tape</p>
<p style="direction:ltr;">1963: Sketchpad, an app as a PhD thesis. </p>
<p style="direction:ltr;">First “mouse” (a light pen)</p>
