A welter of possible buyers for National Semiconductor Corp’s National Advanced Systems Corp have been bandied about, but only four of them make much sense, and its mainframe supplier Hitachi Ltd itself, and fellow Hitachi mainframe OEM customer Comparex Computer Systeme GmbH being the two most likely. NatSemi needs to sell NAS because the company is performing so poorly in the US that it has become a drain on the chipmaker’s core semiconductor business. According to Electronic News, Hitachi, which has showed every sign that it wanted a change of ownership at NAS, has now moved to ease the squeeze on the company caused by transfer prices driven upwards by the soaraway yen – but Hitachi’s real interest is in building volume for its CPU business, and market share in the US and Europe. If it was happy with NAS’ performance therefore, it would have moved on transfer prices much sooner. Hitachi is setting up a slim mainframe support operation of its own in the US, exclusively to look after the local subsidiaries of Japanese companies, but this would be much more cost-effective for Hitachi if it could be combined with NAS. And Comparex has made no secret of its desire to get into the US market. The other two potential buyers who cannot be completely discounted are Unisys Corp – Hitachi supplies Uni sys with key components for the 2200 mainframe line, and with disk drives and other peripherals – can not be ruled out because chairman Michael Blumenthal seems committed to volume at almost any price, re gardless of fit, and Memorex Telex International NV. But Memorex is already deeply burdened with debt, so might find it difficult to raise the cash – and if Unisys were to buy NAS, it would make its decision to float off Memorex in the first place look like a very big mistake.