Evilspeak (1981)

Coopersmith (a suitably miserable-looking Clint Howard) is admitted to a private military academy as a kind of charity case following the deaths of his parents. This being the kind of military academy where the hoary personnel in charge slyly approve of cadets torturing the underachievers, Coopersmith has a rough time of it. For punishment duty (though his crimes, beyond clumsiness, and lateness to class attributable to his classmates stealing his alarm clock, are never disclosed) he is sent to the basement of the abbey to "clean up." The school custodian, an old drunkard named Sarge who happens to live in said basement, doesn't much like this, but what the hell, it leaves him more time for whiskey. Besides, Coopersmith is mostly out of sight, especially after discovering a sub-basement filled with books of black magic. He steals a Tandy TRS-80 from the computer lab, lugs it down to his newfound lair, finds an electrical outlet in a cave otherwise illuminated only by the light of black candles, and starts coding passages from those dusty old pentagram-decorated books into the mainframe. The computer answers! The earliest version of the Internet was a gateway to a Hellmouth, who knew? Some brand of Satan worship ensues, wax dummies spurt red syrup, and at some point a nude woman in a bathtub gets eaten by possessed pigs, I kid you not. A lot of bad data went into the screenplay; garbage in, garbage out.