Subject: Re: Changing serial parameters.
To: None <dgilbert@pci.on.ca>
From: Jason Thorpe <thorpej@SJ.Xenotropic.COM>
List: port-sparc
Date: 11/15/1995 20:11:44
On Wed, 15 Nov 1995 21:57:32 -0500 
 dgilbert@pci.on.ca wrote:

 > 	I would like to see the following change commited... change
 > ZLRB_RING_SIZE to 4096 and ZLRB_RING_MASK to 4095 in zsvar.h.  I have
 > made this change at someone's suggestion and it works like a charm.
 > On my Sun4/260, I can't run PPP at 19200 w/o this change.  The current
 > size is 256.

Might be a reasonable thing to do.  I also thought I noticed another port 
do this to their zs driver...

 > 	For those who don't know... what this changes is the size of
 > the secondary fifo (called the ring in this case) for the serial
 > ports.  It almost entirely eliminates complaints about the keyboard
 > and mouse... and makes it such that PPP at 19200 works.

Cool ... no more fifo overruns when I move the mouse for the first time 
after I run the X server :-)

 > 	The next thing that I'd like to know about this mess is
 > whether or not the priority (or somesuch) can be bumped on this thing.
 > My 68030 based Amiga manages to run 19200 w/o any loss without even
 > the help of a fifo on the serial port.  Why is the Sun4 (about 2 times
 > faster) having problems?

Actually, I've always been under the impression that Amiga's had Really 
Buff serial ports in general...Also might be a side-effect of the way 
interrupts are handled.

And, really, a 4/260 is twice as fast as an Amiga?!  :-)

------------------------------------------------------------------------------
Jason R. Thorpe                                         thorpej@Xenotropic.COM

           Just me and my collection of obsolete computer gear(s).