Amdahl Corp says the sharp rise in turnover for its second quarter (see page six) primarily reflects a steady increase in shipments of the company’s new 5995M mainframe computers, adding that while profits improved, profit margins continue to be constrained by the higher product costs early in the new product cycle and by competitive pressure on pricing, particularly for the older 5995A mainframes; margins should improve in the fourth quarter when many of the start-up expenses are out of the way; first deliveries of the 5995M six-way and eight-way multiprocessors are set for late September; the company will also be ramping up shipments of the new 6390 Model 3 disk drives in the fourth quarter.