# Memory capacity

The `MegabytesOfFreeMemory` setting in the emulator configuration file sets the maximum total heap size in megabytes, in order to emulate target machines with different memory capacities. If this parameter is not specified, the amount of free memory defaults to 64MB.

If you wish to limit the heap, it is conventional to allow one megabyte for EPOC system use: for example, specify 7 to simulate a 8MB machine.