MAXTOR CORP <MXTR.O> BUYS PRIVATE FIRM Maxtor Corp said it bought privately-held Storage Dimensions Inc for an undisclosed sum. The company said Storage Dimensions incorporates Maxtor's high-capacity 5-1/4-inch Winchester and optical disk drives into a family of data storage subsystems for IBM PCs, XTs, ATs and compatibles. Storage Dimensions is the creator or SpeedStor software, a utility program that integrates high-capacity disk drives into PCs. Maxtor said the purchase reflects its desire to compete in the high-capacity segment of the PC market.