Spotting a potential buyer for Ashton-Tate Corp is difficult because it’s hard to see how a software company can find $300m of value in the Ashton-Tate user base – the planned Lotus Development Corp-Novell Inc would likely find one of the string of Unix relational database companies a better bet – but one company that has consistently put volume at the top of its list of priorities and only worries about how to integrate the product line after it has made an aquisition is Computer Associates Inc, which might well see Ashton-Tate’s business worth adding to its own microcomputer software operations.