Extended input/output circuit board addressing system

摘要: An extended addressing system for allowing use of existing circuit boards but obtaining more address space is disclosed. If given bits (A8,A9) in the value indicate that a former board being presented, previously unutilized higher order (A12-A15) are used as slot identifier slot's AEN signal made low, while all remaining signals to each other high disable operation. All lines (72) remain low if an presented or memory operation occurring. go during DMA