Tandy Corp this week opened a new $11m highly-automated personal computer plant in Fort Worth that will turn out 5,000 machines a day and could go as high as 7,500, replacing two existing plants with total capacity of 2,500 a day, but taking only the same 500 people to do the work: it already makes personal computers for Matsushita Electric Industrial Co to market in the US under the Panasonic name, and the two are jointly developing a lap-top for launch later on this year; Tandy also said that its Grid Systems subsidiary believes it has fundamental patents for portable computers that may have to be licensed by other makers of lap tops.