>> Thor, why on earth do you say that? There's, what, a 3-byte fifo, and
>> 57600 bits/sec at 1 start bit and 1 stop bit comes out under 2k
>> interrupts/sec.  Not at all outrageous for a 25Mhz r3000.
>
> Isn't it the 85230 that has the 3-byte FIFO, and the plain 8530 with just 1
> byte?

Though I have no info. about the original 8530, my Personal DECstation
(MAXINE) has a 85C30 chip which has 3 deep receive FIFO.  DEC3000/300
has two 85C30s and I guess 3MIN and 3MAX+ have the same controller
chips.  I donno why Mach source codes refer to Intel chip. 

Tohru Nishimura
Nara Institute of Science and Technology