PERSONAL computing giant Compaq will fire the latest salvo in the on-going PC price war today when it unveils a new line of systems aimed squarely at the lucrative business market. They will be priced as much as US$500 less than the older models they replace. The new series, which is called the Deskpro XL, represents a complete revamp of Compaq's premium product line. It involves an overhaul of everything from chipsets to new outer casings. The Deskpro XL systems are based on the 50 megahertz (MHz) and 66 MHz versions of Intel's popular 486 microprocessor, as well as the 60MHz and 66 MHz versions of Intel's flagship Pentium processor. The company said models incorporating Intel's new 100MHz 486DX4 chip, and its 90MHz Pentium would be released later in the year. The launch is expected by analysts to intensify competition among 'premium' lines of PCs which are aimed at business customers. Pricing on the new Deskpro XL systems brings to the high-end of the PC product market the same kind of aggressive positioning that has characterised Compaq's assault on the low-end of the market. The firm is seeking to achieve the same kind of unit sales volumes at the premium end as it does at the 'consumer' end of the market. Its continued price aggression signals the firm's on-going obsession with increasing global market share. Indeed, Compaq chairman Benjamin Rosen and chief executive Eckhard Pfeiffer aim to make Compaq the world's largest personal computer manufacturer by 1996, an immovable goal the two executives set for the company last year. Some analysts have had lingering doubts about Compaq's ability to achieve such a lofty target, but Mr Rosen and Mr Pfeiffer have shown no sign of backing off. The company still has some way to go - last year Compaq commanded 8.5 per cent of the market compared to IBM's 11.5 - yet it is clearly headed in the right direction. According to International Data Corporation figures, Compaq's 8.5 per cent market share was more than double the 3.5 per cent the company commanded just two years earlier. IDC says Compaq is still growing at twice the industry rate, which should mean it surpasses Apple this year as the second-largest PC firm, and close the gap with IBM. The Deskpro XL has a number of design features built into the systems. Compaq claims it means they are more flexible and the easiest to use business computers on the market. All the Despro XL series are designed to be used either as a desktop or in a tower configuration. And the PC speaker and microphone have been built into the system's keyboard. Connections for the mouse and business audio have also been duplicated on the keyboard, so that, when the PC is placed as a 'tower' on the floor, access to often-used connectors is still simple. For multimedia configurations, Compaq includes a carrier-free CD-ROM drive that accepts CDs either horizontally or vertically, depending on how the system is stored. The company has also included PCI local bus, significantly improving the system's graphics' performance over the Deskpro M series it supersedes. Compaq also claims significant performance improvements through a new PCnet-SCSI chip it developed in conjunction with Advanced Micro Devices. The PCnet-SCSI chip is the first to integrate 32-bit SCSI controller and 32-bit Ethernet on the PCI local bus on the motherboard. This saves not only the expansion slots that would otherwise be needed for the SCSI and Ethernet add-on cards, but the costs of the add-on cards, which would, typically, run to hundreds of US dollars. Meanwhile, Compaq last week claimed market leadership in the server market, citing IDC figures that put its worldwide market share at 37 per cent, ahead of IBM, which claimed 32 per cent, and next-best-placed HP, which claimed a 10 per cent market share. Also citing IDC, Compaq claimed leadership in the superserver market with 64 per cent of worldwide superserver sales, with the next rated company, ALR, with 7.7 per cent. Compaq became the first PC vendor to launch a multiprocessor 'server' system when it launched the first of its Systempro series in 1989.