Evilspeak (1981)

Remember the little kid you used to pick on? Well, he's a big boy now.

In this chilling horror film, a young, misfit, military cadet suffers constant torment by his classmates and dreams of nothing but revenge. When he discovers an ancient satanic temple, with it's attendant secrets, his vengeful fantasies become transformed into a violent reality. Combining the temple secrets with his advanced computer skills, he begins to beckon forth demons and cast evil spells on the objects of his hatred, securing the ultimate revenge.