Newly Released Documents Shed Light on the Tactics Used by Microsoft
New details about tactics Microsoft Corp used to secure dominant role in software markets for nearly two decades are emerging in consumer class-action trial in Minnesota; among documents introduced is letter from June 1990 in wich Microsoft chairman Bill Gates told then Intel chief executive Andrew S Grove that any support given to software company Go Corp would be considered aggressive move against Microsoft; other evidence presented by plaintiffs' lawyers gives account of how Microsoft violated signed secrecy agreement with Go and showed that Microsoft possessed technical documents from Go that should not have had access to; Microsoft spokeswoman says many of newly disclosed documents are not relevant to trial, which focuses on Microsoft pricing actions (M)