Re: /dev/cua* and /dev/ttyS*

[Ed Down <E.M.Down@city.ac.uk>]

I don't know much about how it all works, but I'm sure
/usr/doc/HOWTO/Serial-HOWTO gives a reasonable explanation of cua/ttyS
matters - it convinced me anyway!

Ed





> 
> There have been various mailings here along the lines of
> /dev/cua* names are deprepcated in favour of /dev/ttyS*.
> 
> I was just wondering why the change (and when).  I thought it used to
> be that ttyS* was dial-in and cua* was dial-out (or possibly
> vice-versa).
> 
> I looked in /usr/src/linux/Documentation,  and the only reference
> I saw was in devices.txt which stated:
> 
>   4 char	TTY devices
> ...
> 		 64 = /dev/ttyS0	First serial port
> 		      ...
> 		127 = /dev/ttyS63	64th serial port
> 
>   5 char	Alternate TTY devices
> ...
> 		 64 = /dev/cua0		Callout device corresponding to ttyS0
> 		      ...
> 		127 = /dev/cua63	Callout device corresponding to ttyS63
> 
> 
> I was just wondering,  what exactly has changed,  and why?
> 
> Richard
>