Scrollback and DEC-Talk Express

[John covici]

In the old days the buffer was much larger -- and I think the Dec Talk
Express was using xon-xoff or maybe its using them now and was using
rts/cts before.  Increasing the buffer size to 12k will at least make
the problem go away for most cases.  Now there is another problem and
that is if there is a lot of characters with no space or word
delimiter then you can get into trouble because this will introduce a
buffer overflow.  I have not tested this for a while, so maybe this
one was fixed.

on Saturday 07/26/2008 Tony Baechler(tony at baechler.net) wrote
 > Kerry Hoath wrote:
 > > Handshaking with the dectalk express has allways been a problem; in fact 
 > > asap would lock up nicely if you used the type command to read a long text 
 > > file.
 > >   
 > 
 > 
 > 
 > Hi,
 > 
 > Your explanation was very interesting and was exactly what I was trying 
 > to figure out.  Yes, the kernel has a scrollback buffer, which is what I 
 > wanted to know in the first place.  However, you seem to be overlooking 
 > something or I'm not understanding.  I'm not feeling well so it could be 
 > my fault.  That is that in very old versions of Speakup from cvs, I 
 > could easily cat those same README files to the exact same synthesizer 
 > and speech would go on forever.  I once let it read every single boot 
 > message from the kernel starting to the login prompt with no problem.  
 > It's only now in newer git versions that the 4 KB bug shows up, so I 
 > still consider it a bug that hasn't been fixed.  I admit that I know 
 > little of handshaking and serial communication, but before there was no 
 > problem and now there is.  This can be easily demonstrated with the grml 
 > 1.1rc1 live CD, which still had unlimited text output with speech not 
 > stopping.  Apparently the final 1.1 release upgraded the Speakup version 
 > so probably has the bug.  I don't know exactly when the bug happened but 
 > it goes back to my kernel build from the April git clone and probably 
 > before that.  I don't remember if the Shane Etch CD has this or not, I 
 > would have to check.
 > _______________________________________________
 > Speakup mailing list
 > Speakup at braille.uwo.ca
 > http://speech.braille.uwo.ca/mailman/listinfo/speakup

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici at ccs.covici.com