ARRANGEMENT FOR EXPANDING MEMORY CAOACITY

摘要

The invention includes one or more circuit cards, each of which can be plugged into a data processing system and each of which can have multiple banks of memory thereon. In a preferred embodiment, a system can have up to two cards and each card can have one, two, or four banks of memory located thereon. In addition each circuit card includes signal generating circuitry which generates a plurality of electrical signals, which signals, when considered together, represent a code that indicates the amount of memory located on the circuit card. Further, in addition, each circuit card has combining circuitry thereon which is connected to receive the last mentioned coded signals as well as coded signals from a second circuit card if the same be plugged into the data processing system. The combining circuitry combines the two sets of coded signals to provide a resultant set of coded signals which are indicative of the total amount of memory on the two cards and the addressable location of such memory. The data processing system with which the circuit cards are used provides the circuit path to connect the circuit cards.