push edx
push ecx
push ebx
mov eax, 'VMXh'
mov ebx, 0 // any value but not the MAGIC VALUE
mov ecx, 10 // get VMWare version
mov edx, 'VX' // port number
in eax, dx // read port
// on return EAX returns the VERSION
cmp ebx, 'VMXh' // is it a reply from VMWare?
setz [rc] // set return value
pop ebx
pop ecx
pop edx