How to float I/O signals of EP910 devices

Thanks. I do find many commercial programmers that can handle EP910 devices.

However, if the devices being tested are already programmed, and security fuse blown,

then erasing them is not an option and I would still need a way to float all I/O.

Altera usually publishes low level details of how to program any device

(to enable people to design their own device programmers), so that information is got to be somewhere

and that is what I am trying to find.

a. Does the device float its I/O pins when erased ?

b. Is there a way to float I/O pins without erasing the device ?