High speed serial (was Re: Amiga 3000UX, X, OpenLook, ... )

[Bernd Felsche]

In <dillon.5445 at overload.Berkeley.CA.US> dillon at overload.Berkeley.CA.US (Matthew Dillon) writes:

>    Also, don't forget that most UNIX machines have major problems with
>    baud rates above 19200 when using a direct-interrupt scheme.  Most
>    multi-port solutions these days have co-processors, hardware SILO's,
>    etc, etc, etc... even so it is still possible to overrun the buffer
>    capability on most UNIX boxes, especially loaded down ones.

Even unloaded machines, with intelligent IO processors have problems.
On our Motorola MVME174-based machine with an MVME332XT serial card,
hooking TXD to RXD on the same port, then feeding it data at 4800bps,
and then reading it back, causes it to fall over... not just the data,
but the whole system.

(Why I tried this is an entirely different story, suffice to say, it
was the only port available.)

Don't try this on your own system. It causes many frowns!

Obviously, something became unmanageable with the c-lists and the
kernel PANIC(8)ed.

>    Matthew Dillon	    dillon at Overload.Berkeley.CA.US
-- 
Bernd Felsche,                 _--_|\   #include <std/disclaimer.h>
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