Meantime Unisys Corp has bowed to the pressures of the market and yesterday cut prices 47% to 66% on its entire line of PW2 Advantage personal computers, and unveiled a new model. The new PW2 4256 has a 25MHz Intel 80486SX processor and costs $2,200 the same starting price as DEC has set for its 66MHz 80486DX2 model. An entry level 80386SX box is $800.