For the first time in years, hardware startups are trying to break into the market. Their gambit: Inexpensive special-purpose machinesSPECIAL REPORT: NEXT-GENERATION COMPUTERS>> Steve Dewitt remembers an incident that occurred soon after he joined startup Azul Systems three years ago. He walked out to the driveway of his Silicon Valley home to pick up the morning newspaper and ran into a neighbor -- Bob Evans, a legendary former IBM (IBM) executive who oversaw the development of the mainframe computer in the 1960s that led to Big Blue's industry dominance. Dewitt had recently told Evans of Azul's plan to create a...