The TI-99/4a capture my interest when I was just 14 and I have been involved with it ever since.
I ran USS Valiant II back from 1985-1988 with Mark Shields BBS program called S.O.F.T.W.O.R.X which was powered by Zyolog Machine Language.
I actively code programs within .NET for Windows machines and of course TI Extended basic.
Check out my Software section for Cartridge Manipulator for Windows.
I currently have a 99/4a system that I am always expanding some how and I am currently coding a new BBS that uses S&T machine code with permission from the author.