Customers holding fire as they wait for new generation machines, notably the new 2200/600 and 2200/400 mainframes in the 1100 family, mean that first quarter profit at Unisys Corp will be very weak, the company says, although orders for the new machines were strong in the 1988 fourth quarter, so the latter part of the year should show big benefits from heavy shipments of the new machines; the very dull fourth quarter figures (CI No 1,102) would have been even worse but for the tax rate for the period falling to just 18.7% from 38.4%.