I think this has been brought up before but Google not helping.

Did I read once about the possible existence in Sun HQ of a JAva-based
Sunray DTU emulator? Would be nice to have on for testing purposes,
especially for this Wanray project I'm doing!

Must be quite easy since a DTU has a very tiny brain with what must be
only a tiny amount of code. The Sparc emulation might be hard tho - I
dunno, i'm no proggie....