Suppose situation. At some point of the game, corp has both, revealed and unreveald at graveyard (archive). When then corp plays archived memories, he/she doesnt have to reveal card, which is being looked for. The question is whether cards from graveyard (archive) , which were unrevealed, become revealed after archived memories play ?

Get outta here with your Magic terminology ;-)

I'm only half-kidding; the rules are written with specific terms that interact in specific ways. "Revealed" means something different, and rules that govern the Corp's *Archives* are different than ones which refer to the runner's *heap.*

And therein lies your answer: since REVEAL has nothing to do with FACE-UP or FACE-DOWN cards in Archives, the cards remaining are unaffected by Archived Memories. Face-down cards in Archives are only turned face up when the runner accesses archives (usually during a run).