There is an error in the code that however does not prevent the correct execution of the simulator. You can fix by yourself if you want to.
err: char ps = (WORD * )&vid; // video memory pointer
err: char ls = (WORD * )&vbtmp; // line buffer pointer
fix: char ps = (char * )&vid; // video memory pointer
fix: char ls = (char * )&vbtmp; // line buffer pointer
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