PTYs

Ken Moffat ken at kenmoffat.uklinux.net
Wed Feb 18 03:48:00 PST 2004


On Wed, 18 Feb 2004, Albert Reiner wrote:

> Hi,
>
> by now I have successfully completed Chapter 5 of LFS 5.0, and am in
> the early stages of Chapter 6.  Before I go on, however, I want to
> make sure I understand at what point I can prevent some annoying PTY
> behavior I am currently facing on my host (Knoppix-installed Debian):
>
> On this host,
>
> - the pseudo terminals use a ridiculously small font (48 lines, 128
>   characters wide),

 I think these are the real (console) terminals.  You're using a
framebuffer in a 1024x768 pixel display, right ?  Each framebuffer uses
different syntax to set it up, but from experience if you don't tell it
a setting, or one that it recognises, most default to 80x30 or perhaps
85x35.

>
> - scrolling is extremely sluggish (to the point that I have turned to
>   switching consoles when some process produces a lot of output),
>

 Or maybe just build the kernel without framebuffers if you only want
80x25.

 Framebuffers definitely seem to slow things down a bit, but on most
hardware they'll still comfortably outpace what you can read.  What cpu,
memory, which framebuffer ?  The "lowest common denominator" (VESA, I
think) seems to be particularly slow.

> I wonder whether devpts might have something to do with the problems -

 /dev/pts is used in some of the testscripts when you build the
packages, and also for xterms and consoles when you log in over ssh.
I'd be _very_ surprised if umnounting it gained you anything.

 If I could swap your 128x48 with my 80x30 on my radeon 9200se we'd both
be happy ;) (and before anybody asks, looks like this is a kernel
problem at my end, _one_ day I'll finish reviewing what isn't in the
tree I have to use for that box.)

Ken
-- 
Brighton tops UK Jedi league
http://www.theregister.co.uk/content/28/35186.html




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