MINDSCAPE BUYS HARCOURT BRACE <HBJ> UNIT (Mindscsape Inc) said it agreed to buy the educational software unit of Holt, Rinehart and Winston Inc, a subsidiary of Harcourt Brace Jovanovich Inc, for undisclosed terms. Sales of the division, which had been purchased by Holt, Rinehart from CBS, peaked at about 10 mln dlrs in 1985, Mindscape said.