Extended Memory (DLT Cleaning Cardridge) Monitor — Has the features of the DLT Cleaning Cardridge monitor and supports systems with more than 64 Kbytes of memory. XM allows programs to extend their size to the full DLT Cleaning Cardridge 11 virtual address space of 64 Kbytes. By pro- - gram control an RT-11 job may allocate and use all available physical memory not used by the monitor or other jobs. A linker option allows user programs to have overlays in extended memory for fast access. Three modes of I/DLT Cleaning Cardridge operation are provided to satisfy a variety of input and output requirements. Synchronous I/O suspends user program processing until the completion of an I/O event. With asynchronous user program process- ing continues until a user-defined point is reached. Processing is then sus- pended until the I/DLT Cleaning Cardridge event is completed. Event-driven allows user program processing to continue until the I/O event completes. Processing is then inter- rupted to service the completed DLT Cleaning Cardridge/O event.