As the subject says...

My impression of the "standard 432/9 to 432/10" upgrade is that the older IO-card fitted to the machine from the factory can still be used? (If so, one does not have to rewire or make a adapter connector.)

If im right about the above, is it only a matter of MC settings to make the partly new and partly old controller to run happy together or is some hardware work needed?

Im trying to get my old 432/9 MH500C benefit from a scrapped MH600E2 controller. Got all the control cards so im sure its doable.

Happy to pay for the right information if its simple enuff to solve by PM/mail/phone.
Additional information can be provided if requested.