WHILE preaching the virtues of computer ''downsizing'', the American personal computer manufacturer, AST Research, has ''upsized'' its product line with the launch of its first multi-processor systems. The company, which was founded in 1980 making fairly simple PC add-on card products before progressing to system level in 1987, has progressively moved to more and more powerful products. The so-called Manhattan SMP takes AST further up the performance ladder, being aimed squarely at the market segment currently occupied by proprietary minicomputer architectures, or at competing super-server products like those from Compaq Computer. ''In Asia, we are really looking at these as a minicomputer replacement product,'' said AST Research's Asia/Pacific managing director, Mr Philip Wong. ''We really are moving up from the PC to minicomputer-sized systems.'' The first Manhattan SMP products will house up to six Intel 80486 DX processors, with a starting price of about US$27,000. The systems will run various operating platforms. AST launched the Manhattan in the US late last year, but held back its Asia launch as it re-designed distribution channels to target what was an entirely new market sector for the company, Mr Wong said. ''We really had to spend a lot of time getting our dealers ready for this - doing all the training and getting stocked up with spare parts inventories.'' Manhattan will be available in volume in Hongkong in June.