I'm going slightly mad.... :-) :-)

Example from Keil: FarMemory, 16MB RAM on ADuC812

Add this declaration before void main (void):

far long xyz, ghi ;
long abc, def, jkl, mno;

Add this in the endless loop:
while (1)
{
abc= xyz++;
def= ++ghi;
jkl= mno++;
}
Add all variables to watch, set breakpoint in the loop, and ... enjoy!