This applet is based on one of the first pieces of Java code I downloaded from the net. It was originally written by Nigel Gamble under the name HexCalc, and didn't have two memories, square root, or binary or octal modes at first (I think). Those were extensions I put in. I also changed it to use the JavaDoc:java.math.BigInteger class in order to gain arbitrary precision - the display can be scrolled to view large numbers. The square root algorithm is taken from a post by John Bruner.

The class also runs as an application. The source code is available here

You must turn on Java for applets to work.