A Swiss company, working with memory chipmaker Hynix Semiconductor, has introduced a design that it says will be a cheaper, lower-power replacement for the common computer memory known as dynamic RAM, or DRAM. Innovative Silicon, in Lausanne, says it has redesigned its zero-capacitor RAM, or Z-RAM, so that it can be built on the same kind of wafers used for ordinary DRAM. This is a big advance for