System for swapping in and out of system memory TSR programs by trapping interrupt calls for TSR and simulating system interrupt

摘要

A method for the allocation of RAM memory space in a microcomputer environment allows for one or more terminate and stay resident (TSR) or other programs to be stored on a remote memory device in a way that preserves their accessability. The method includes the installation of a supervisory program which traps calls for a displaced program and transfers a portion of another program, such as an application-type program, in RAM to remote memory while retrieving the called displaced program from remote memory into the RAM space previously occupied by the transferred portion. The swap function is performed in a manner which preserves the integrity of the swapped program, and which allows operation of the application program to be halted such that it may be restarted without loss upon return from remote memory. In another aspect of the invention a communication TSR is simulated to allow data transfers to the TSR to be processed even if the TSR is in remote memory.