Embarrassed Unisys Corp officials had to admit last week that they had been completely in the dark about the plan for Ardent Computer Corp to create Stardent Inc in a merger with Stellar Computer Inc. The embarassment arose because – despite its avowed commitment to make more of its gear in-house – Unisys had agreed to buy graphics minisupercomputers OEM from Ardent only days before. No financial details were revealed, but Unisys will use the Titans – and also likely forthcoming Stiletto graphics machine and new minisupercomputers in its Federal Information Systems division, which has contracts that need that kind of system.