Parallel port isolation

The notion of using the Parallel port to control machinery has fascinated me
for 15 years. However, as one who obeys speed limits and never uses stairs
without holding on to the rail, I am naturally concerned about hooking my
non-isolated parallel port I/O to an 80 volt amplifier controlling inductive
devices.

Has anyone experienced fried computer syndrome from stray currents in large
stepper systems? I know this can be a problem with servo systems, usually
from ground loops.

Doug Harrison