Hewlett-Packard Co this week introduced the Vectra QS/16, billing it as its most powerful desk-top personal computer. The 16MHz AT bus 80386-based machine, which is $4,000 with one floppy, was intended to come out in May, but was held up by the memory chip shortage. It is the existing Vectra RS/16 repackaged as a small desktop machine, and runs OS/2, Windows/386 and Santa Cruz Operations’ Xenix as well as MS-DOS. It also costs $900 less than the floorstanding model when fitted with a 40Mb disk. It uses surface-mount technology for reliability as well as compactness. Memory goes from 1Mb to 16Mb on the motherboard, freeing all seven expansion slots for accessories and enhancements. It also includes terminal-emulation software that enables it to communicate with HP3000 business computers. The 40Mb disk model is $5,100 and also comes bundled with an HP video graphics adaptor and choice of 5.25 1.2Mb or 3.5 1.44Mb floppy drive for $5,500. Out this month in the US.