how can i simulate two 89c52 codes at the same time?

hi,

let me elaborate a bit on my topic...

my aim is to actually simulate two independed codes of 80c52 uC's in software. from what i have observed and experienced, software do simulate the uC's operation but only do it on a single hardware basis - that is only one uC code is simulated per session.

is there any simulator that would allow at least two kinds of code to be simulated at the same time such that communication between two uC's can be seen?

thanks...