DOTRONIX INC <DOTX.O> TO BUY <VIDEO MONITORS> Dotronix Inc said it agreed in principle to buy Video Monitors Inc, a privately-held company. In payment for the acquisition, Dotronix will issue 312,500 unregistered shares of its common stock, notes worth 1.8 mln dlrs payable over three years, and about 70,000 dlrs in cash. Dotronix said Video Monitors' sales for the fiscal year ended April 30, 1986, were 7.6 mln dlrs. Dotronix had income of 659,663 dlrs on sales of 7.1 mln dlrs for the six months ended Dec. 31, 1986, as previously reported.