[ale] DIY Graphing Calculator Is Built From Open Source Hardware

[jcpilman at gmail.com (jcpilman at gmail.com)]

I still have a couple of slide rules which I began using before high
school.  My wife owns a circular rule that does not have sliding
disks, but instead has two movable cursors (not sure they were called
cursors).  It worked on the basis of constant angle between the
cursors.  A 10 inch circular slide rule has the precision of a 25 inch
linear slide rule.

...John