>I have a question guys, It is regarding those decstations that can't boot 
>via tftp, Is the problem that these decstations don't support tftp at all, 
>or is it that they have a bug?

They have a bug.  More precisely, _some_ PROM versions on _some_
models have a bug which means they can't boot successfully via TFTP.

That's why Simon constructed and maintains a list of which PROM
versions, on which models, are buggy.

As best I recall from V-kernel days, still other versions on other
models (some later 3100 proms? I forget) have bugs which means they
cannot boot large second-stage bootloaders via PM.