speakup and serial hubs?

[Chris Gray]

Hi Justin:

Due to the nature of the RS232-C serial specification, there are 
complications about having something put together like a serial hubb. 
The serial hardware alone takes a fair amount of electronics, the way 
way serial ports are implemented through the motherboard doesn't lend 
itself to a hubb like you see today with USB devices.  It's a creative 
question though.

Before USB, there were lots of board made that attempted to do what you 
are suggesting, or variants of that.  Enough serial devices still exist 
that you might be able to find such a device today.  Typically, these 
were boards that had 4, or more separate serial ports on them, with a 
ton of jumpers to modify IRQ and port addresses.  Beware of cards with 
connectors that are just nullcross-overs for the same port; those won't 
help you.  You must have separate, discrete ports and 
connectors/jumpers to them.

whether you can find such a card that's both PCI and 
affordable is an interesting question. I called a local, relatively 
large computer store here in San Francisco Central Computers, because 
all this made me curious and they have fairly decent customer service. 
I'm slightly surprised, but It turns out they have a high speed i/o card 
with two ports for $19.99 from Vitex, it's even in stock!  If they carry 
it, I bet you could order something from Comp USA if you've got the 
patience, or find something localy or online.

Hope this helps.

Chris

On Thu, 6 Jan 2005, Justin Ekis wrote:

> Date: Thu, 6 Jan 2005 16:44:01 -0500
> From: Justin Ekis <jekis at fastmail.us>
> Reply-To: Speakup is a screen review system for Linux.
>     <speakup at braille.uwo.ca>
> To: speakup at braille.uwo.ca
> Subject: speakup and serial hubs?
> 
> Hi all,
>
> When I had this computer built, they only put in one serial port, which is 
> used by my doubletalk LT for speakup.
> My braille lite m20 is finally fully supported by brltty so when the new 
> version gets into Debian I'd like to use it. Also the proprietary driver for 
> my winmodem still hasn't been updated for Linux 2.6 so I'd like to buy a real 
> modem.
>
> I guess the term for what I have in mind would be a serial hub. Something 
> where you could plug into a serial port and plug three or four devices into 
> it. Is there such a thing and would Linux and speakup work with it? Would I 
> be able to use all three at once?
>
> Justin Ekis
>
> _______________________________________________
> Speakup mailing list
> Speakup at braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>

-- 

Chris Gray, Sr. Technical Writer        Symantec Corporation
415-365-6199 voice                      301 Howard Street, Suite 1800
415-348-9636 fax             		San Francisco, CA 94105