Tandy 1000 Basic Reference Manual page 117

Chapter 10
I
BASIC Ke.ywords
To draw an ellipse that is wider than it is high, use an aspect
ratio that is less than the default value for that screen mode.
The smaller the aspect ratio you specify, the wider and shorter
the ellipse. For example, in Screen Mode 1, an aspect ratio of 1/2
gives you an ellipse like this:
To draw an ellipse that is higher than it is wide, use an aspect
ratio that is larger than the default value for that screen mode.
The larger the aspect ratio that you use, the taller and thinner
the ellipse. For example, in Screen Mode 1, an aspect ratio of
716
draws an ellipse like this:
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