Subject: Re: Serial changes 1.1-current
To: None <thorpej@nas.nasa.gov>
From: Christoph P. Kukulies <kuku@gilberto.physik.rwth-aachen.de>
List: port-i386
Date: 05/04/1996 09:53:55
> 
> 
> On Fri, 03 May 1996 21:01:41 -0400 
>  "Perry E. Metzger" <perry@piermont.com> wrote:
> 
>  > Sun 3/60s have far superior serial hardware to PC serial hardware. PC
>  > serial controllers are nearly the worst imaginable. Getting the things
>  > to operate well is very hard -- the Linux folks had to alter the
>  > entire tty driver to do it.
> 
> *cough* *spew coffee*
> 
> The Zilog 8530 *SUCKS*  I'd take a 16550 over it *ANY* day!  :-)

Don't forget that the 8530 supports HDLC (bit serial protocols) which the
16550 doesn't. And there are some 16550 (SMC? SMS?) which behave differently.

> 
> Now, 16550 on an ISA card may very well chomp rocks, but that's probably 
> due to the i386's (hardware) lame-o interrupt system :-)
> 
> The 16550-alike on my hp380 (the one with the FIFO ... there's also a 
> 16550-alike for the hp300s without a FIFO, found on earlier models) can 
> do 38.4k without much of a problem at all.
> 
> There are other things that can be done to the NetBSD kernel to improve 
> serial performance as a whole, and they've been discussed on tech-kern 
> before.
> 
> ----save the ancient forests - http://www.bayarea.net/~thorpej/forest/----
> Jason R. Thorpe                                       thorpej@nas.nasa.gov
> NASA Ames Research Center                               Home: 408.866.1912
> NAS: M/S 258-6                                          Work: 415.604.0935
> Moffett Field, CA 94035                                Pager: 415.428.6939
> 

--Chris Christoph P. U. Kukulies kuku@gil.physik.rwth-aachen.de