Toshiba Corp claims it’s the first company to introduce a new breed of mini-notebook systems into the US with the much- anticipated debut the Windows 95-based Libretto 50CT PC, which weighs in at 1.85lbs. Toshiba, which sold 2.85 million portable and notebook computers in 1996 compared with 1.4 million in 1995, has sold a slightly smaller version of the brick-sized device, which is one inch thick, in Japan for sometime. The $2,000 device, which ships in June, uses a 75MHz Pentium and comes with 16Mb RAM, 760Mb drive and a 6.1 active matrix screen. The fact that it runs a fully-enabled version of Windows 95 is expected to make it attractive for business users compared with other ultra- lite devices which utilize Microsoft’s cut-down Windows CE operation sytem. The Libretto is just one of half a dozen new Universal Serial Bus-based portable PCs Toshiba introduced yesterday, each of which are smaller and lighter than previous models.