Hewlett-Packard Co's Portable Vectra CS and Vectra CS Model 20 demonstrate HP's engineering expertise, but some aspects of their design may limit the products' success in the market. The $2,495 Portable Vectra CS is based on an NEC V30 microprocessor running at 7.16 MHz and includes a slot for a math coprocessor, two PS-2-compatible 1.44Mbyte 3.5-inch disk drives, 640Kbytes of RAM, and a 12-inch super-twist liquid-crystal display with 640-by-400-pixel text resolution. The Model 20 uses a 20Mbyte hard disk drive in place of the floppies and costs $3,595. The systems include a gauge to show the battery life left, the ability to attach a monochrome, CGA, or EGA monitor, and capacity for up to 6Mbytes of EMS RAM (4Mbytes in the Model 20). The machines are large for laptops and lack backlighting in their displays, but their power and design features make them well worth considering.