Control Data will convert its disk drive...

Control Data will convert its disk drive operations into a separate subsidiary, a possible prelude to a sale or partnership for the unit. Analysts said the unit accounted for nearly $1 billion of the company’s $3 billion in revenue last year. Disk drives are devices used for storing and retrieving computerized information at high speed. Louis Lundberg, a company spokesman, confirmed the contents of a June 29 memo from Lawrence Perlman, a Control Data executive.