Method for communicating information between independently loaded, concurrently executing processes

摘要

A subprogram which operates as a MS/PC-DOS device driver provides a communication path between a data acquisition program which operates as an interrupt driven memory-resident program in background and a conventional data analysis program which operates in foreground. Information transfers are initiated by the foreground program which issues standard I/O requests to the DOS, identifying the device driver and the information storage area within the foreground address space from which or to which the information is to be communicated. The device driver subprogram relays the information to the background process by calling the background program at an entry point which is made available to the device driver at a predetermined interrupt vector location, enabling the device driver to pass the memory address of the foreground storage area, together with the size of the block of information to be communicated, to the background program. The background program operates in a selected one of several possible modes, one of which waits for data to supplied from an external data acquisition instrument before returning control to the foreground process so that the two processes can operate in synchronism.