Micropolis Corp saw $4.375 sliced off its share price Monday and Tuesday this week to leave it at $18.50 as the Chatsworth company warned that second quarter net profit would not match the 60 cents a share of the same period last year – or the 63 cents a share achieved in the first quarter: the company blames increased competition in the disk drive market – where it has major OEM contracts with AT&T Co, Sun Microsystems and Compaq Computer Corp, and the fact that it has taken longer than it expected to get the costs of manufacturing its 1500 series 380Mb drives down; the company did $6.8m net on sales of $70.9m in the second quarter 1987, and saw first quarter 1988 net up 16% at $7.2m on $80.5m turnover.