* When using the Desktop the OS uses the RAM between &A000 and &BFFF (8 KB).
* In case an application is running the RAM that is used by the OS can be reduced to the region between &B800 and &BFFF, in this case only 2 KB are occupied by system variables of the OS.
* Depending on the amount of active drives and HD partitions additonal additional expansion RAM blocks will be occupied for directory buffering, but there is no reduction in free main memory (first 64 KB). After loading data this buffers can be freed again of course.
* FutureOS provides all needed functions to check for, order, allocate and manage expansion RAM up to 4 MB. Also files of that length can be loaded and saved at once.