The Silicon Valley computer-tape and floppy-disk maker said it is seeking to consolidate operations. The cutback affects about 2% of the company's 11,000 employees. About 125 of the employees involved worked in the Silicon Valley, where Memorex has 4,300 employees, Memorex spokesman Russ Louthian said. Only middle-management employees--those not directly involved in manufacturing, sales or service--were laid off, the company said. In another layoff action, Zymos of Sunnyvale, Calif., announced that it has reduced its work force by 119 employees, leaving the total number employed at 198.