I may be asking a dumb question, but why do you need a 576 if you want a curve tracer?
Could you not do the same thing with 2 computer controlled power supplies?
That and some software could characterize any 2 or 3 terminal DUT that a 576, 577 or even
a 570 can do. It is not as if the Tek curve tracers are fast, i.e. they plot at 60 Hz.
The computer controllable supplies would need to have programmable voltage and current
and be able to read the voltage and current. That does not seem to be too much of a