Remote Initial Program Load - RPLOADER and DR-DOS

RPLOADER and DR-DOS

In addition to this "RPL" interface, DR DOS supports a more flexible extension named "RPLOADER". If DR DOS detects the presense of RPLOADER rather than RPL only, it starts to issue INT 2F/AX=12FFh/BX=0005h broadcasts at certain critical stages in the boot process. The RPL code can use them to relocate itself in memory (in order to avoid conflicts with other resident software or to avoid memory fragmentation when the RPL memory is freed later on), or to hook into and better integrate with the operating system in order to perform its final cleanup tasks in a well-defined and coordinated manner through a robust and supported backdoor interface rather than mere hacks. This helps to improve compatibility without having to adapt the RPL code with each new version of the operating system, and it avoids unnecessary memory fragmentation and thereby increases available memory for DOS programs to run. The interface can also be utilized to run DR DOS as a task under a host operating system such as Concurrent DOS.