Lecture on Btrees,
baobab.zip
(applet+lecture, packaged in a zip file).
Note that the applet requires a browser understanding
Java 1.1.6 (like Netscape 4.08 or IE 4.0)
Warning; the lexicographic order is used to compare the
entries of the B-tree
That is, numbers are compared as strings ("124" < "82" !!!).