> Date: Fri, 12 Jan 1996 22:46:11 -0500 (EST)
> From: David Gilbert <pci!jaywon!dgilbert@life.ai.mit.edu>
> To: jaywon!netbsd.org!port-sparc@life.ai.mit.edu
> Subject: Serial port issues on Sun4/260
> 
> 	While I was conversing with a bunch of local UN*X wizards (at
> a little get-together), the subject came round to some of the changes
> that were happening to the Sun4 and why.  The thing that got my
> attention was that the hardware flow control should be asserted by the
> chip when the fifo is running low.
> 
> 	Are the Sun4 built-in serial ports capable of this, and if so,
> how do I instruct NetBSD to turn it on?  I believe that I have ctsrts
> set in most of the config files that allow it (specifically the
> faxgetty and pppd configurations).
> 

The Zilog chips that are used in so many of Sun built-in serial
ports are not capable of automatic flow control. There is no
way to do this from the chip.

-brad w.