Advanced Micro Devices Inc is seeking a manufacturing partner to help it raise output of its Am486 chips next year. The company expects to ship hundreds of thousands of Am486 parts this year and according to vice-president Robert McConnell, the company can expect about a 5% market share this year within its capacity limits, and that to boost market share it will have to find a partner. He would not say what companies were being considered as potential partners, but National Semiconductor Corp has hankered after a hit microprocessor for years, and the Japanese, led by existing Advanced Micro partner Fujitsu Ltd, would no doubt be interested. The company is looking for a 20% share of the 80486-compatible market by the end of 1994 if it is successful in lining up a partner.