I finally went and pulled out the old Texas Instruments TI 99/4A computer that I bought in 2004. I originally bought it for the show, and at last got around to actually testing the system. While I have only three working games (the 4th one was DOA), I am putting the TI 99/4A into the 2010 Underdog area anyway. Why? Because it is a real underdog computer system, and I’ve wanted to have it on display for a while now. The lack of games is not an issue with me (but I hope to pick up a few more at the MGC show). I’ve got three good games, and that works for me. TI Invaders is one of them, and it is a very good Space Invaders clone, with a few unique twists of its own.
Welcome to the Underdog Chamber Mr. TI 99/4A! 
TI 99/4A – TI Invaders
Hi!!! Glad to see this post! My name is Owen and I am an avid collector and game programmer for the TI-99/4a. I have hundreds of games and software items, a few of which I have written. My website, “Opry99er.com” is full of useful info on the machine, and I also have links to many other great TI sites as well. There are a couple great emulators available for the TI… My favorite is Classic99. It very accurately emulates the computer, and there are 10 or 15 licensed ROMs included directly in the program. If I can be of any help, please contact me at owenbrand@opry99er.com. Thanks guys, and have tons of TI fun!!!