Prepares the memory for the simulation. Might take some time.
Maybe you do not have enough physical memory (=memory bars) in your computer. Check the memory requirements:
up to 80x80 grids: 128 MByte up to 100x100 grids: 256 MByte up to 200x200 grids: 512 MByte up to 250x250 grids: 1 GByte (-yes- 1 GB)
Memory is inexpensive in these days and if you want to work in numerical simulation you should invest a few bugs in your computer.
There is nothing which replaces real memory!
No. Dynamic arrays are way to slow for a numerical model.