I know that at least two 8530 uarts can speak with each other at baudrate
   generator value 0 (from a target hardware which even has the same quartz).
   
the z8530 is certainly capable of doing faster tha 38400 ...
   
   So the problem is "you *can* run faster, but you won't get 115k" ?

but not on a sparc.  the clock is the problem.

.mrg.