Memory can be preloaded by typing entries of the form
Then press the 'Set Mem' to initialize the memory values.
Put the starting address in the address box. The memory boxes will start at that address and each one shows 16 cells. Press 'load' to put the program into memory. Then you can either step through it or run it all at once. There is precious little error help.
The rotate instruction appears to be working. Floating point addition is the same as integer addition. There is no ability to alter memory except through instructions. Same with registers.
Try it out and please send comments or bugs to email@example.com .