A microprocessor controlled three-port interface to the 168/E processor

The 168/E is a fast processor, which emulates the IBM 370/168. For many applications one is forced to overlay the processor's memory. The authors designed an interface, which connects the 168/E to a host- computer and a low cost MOS-memory with an address-space of 4 M-bytes. This three-port interface is controlled by the Motorola MC 68000 microprocessor which also manages the execution of the several overlays. Since all control is performed by the 6800 software, the interface hardware is relatively simple. Seen from the host-computer side it connects the host to a 168/E-processor with a large memory. No restrictions are made to the number of program or data overlays. The maximum time spent overlaying the whole 168/E program and exchanging all data is limited to 70 msec. The connection of additional 168/E processors is possible. (5 refs).