This is the great tool from University of Colombo School of Computing which will be a great asset, in the process of using Sinhala/Tamil Unicode.
This converter is available at http://www.ucsc.cmb.ac.lk/ltrl/services/feconverter/
or http://www.ucsc.cmb.ac.lk/ltrl/services/feconverter/t1.html
Sinhla keybord --> http://www.ucsc.cmb.ac.lk/ltrl/services/keyboard/
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Another Converter..
You can use http://unicode.malindaprasad.com/ as a Real time Converter.....
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