Mmmm..;. job of modern OS is to use/manage MMU. Prior to DEC, OS just automated version of human feeding punch cards/spooling up tape. DEC provided the necess

Mmmm..;. job of modern OS is to use/manage MMU. Prior to DEC, OS just automated version of human feeding punch cards/spooling up tape. DEC provided the necessary hardware MMU to do actual real time multi-processing/multi-user access in feasibile/practical manner.