I have a SPARCclassic (sun4m, ROM Rev. 2.9), but I can't access
the serial interfaces /dev/tty{a,b} with NetBSD 1.5.1.

The kernel knows the both interfaces of the Zilog 8530 Dual UART.
During booting I get the following messages: 

	zstty0 at zs0 channel 0
	zstty1 at zs0 channel 1

But it isn't possible to change the parameters of /dev/tty{a,b} though
the program 'stty' doesn't report any errors. Here is an example:

	hostname# stty -f /dev/ttya
	ispeed 0 baud; ospeed 9600 baud;
	lflags: echoe echoke echoctl
	etc.

	hostname# stty -f /dev/ttya ispeed 9600

	hostname# stty -f /dev/ttya
	ispeed 0 baud; ospeed 9600 baud;
	lflags: echoe echoke echoctl
	etc.	

The parameter 'ispeed' has the same value as before. If I do something
like

	hostname# cat file >> /dev/ttya

the machine is hanging and it has to be powered down because interrupting by ^C and
^Z doesn't work any more.

Remark: The Zilog UART is not out of order but it works very fine!
So attaching a terminal and pulling out the keyboard this terminal can
be used as console. Even changing the speed with the Forth Monitor

	ok setenv ttya-mode 38400,8,n,1,-

works if the speed of the terminal is adjusted as well.