drive in movies texas

Front (in-dash) DVD player law in Texas? Is it illegal to play movies while driving?
I just got a DVD player and an LCD screen installed in my dash. I’m pretty sure it’s illegal to have it playing a movie while driving but not sure. If it is, how hefty are the fines in Texas, or more specifically the Dallas area?
I found out the hard way that it is illegal in Houston . I paid a $420 fine last Friday , it sucks . I wasn’t watching , my passenger was . Now , I have to pay to get it removed , and to put in the old radio . Another $200 .
Texas drive in movie memories