I have to say to ANYONE who's interested in "programming" a Virus; read "Virus programming tutorial" on Access-Music's site
http://www.access-music.de/downloads...virustidesktop (at the bottom of the page at the time of this post).
It was written by Howard Scarr, a very talented sound designer, who also made a bank and then some of the ROM sounds in your TI. The paper is VERY easy to follow and EXPLAINS how to create particular categories of sound.