MEMORY SHARING SYSTEM

PURPOSE:To reduce the kind of memory and to set up the capacity of a common area in each local processor, by providing an area commonly used with a master processor, in an exclusive memory for local processors. CONSTITUTION:The master processor has a memory space of 1MB and twenty address lines A19-A0. Since varied in every 16KB, a common memory is addressed by the address lines A19-A14. If a switch SW19 is turned on, an input signal to a gate 102 is turned to ''1'' when the address line A19 is ''1''. When the common area is 16KB, both switches SW1, SW2 are turned on and all the switches SW19-SW14 are available. When the common area is 64KB, both the switches SW1, SW2 are turned off and only the switches SW19-SW16 are available.