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scroll-back tty's

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Laszlo Herczeg

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Dec 5, 1993, 12:34:22 PM12/5/93
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What would it take to implement scroll-back on tty output?
That is, the user could scroll back on the screen output by hitting
a certain key, such as PgUp.

Would it have to go into the kernel, or could it be hacked into
a shell, similar to the way the program "screen" has a
scrollback buffer?




Robert Sanders

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Dec 5, 1993, 1:57:55 PM12/5/93
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l...@whome.uucp (Laszlo Herczeg) writes:

> What would it take to implement scroll-back on tty output?

There is limited scroll-back on virtual consoles. Basically, pressing
shift-pgup and shift-pgdn (default key mappings) let you access other
parts of the circular video buffer. Switching VC's will lose scrollback
because it resets the buffer.

> Would it have to go into the kernel, or could it be hacked into
>a shell, similar to the way the program "screen" has a
>scrollback buffer?

A more complete implementation could be put in the kernel, but I'm
not sure the benefits would be worth the bloat. I can usually get
the same effects using pagers when I need scrollback. Other
approaches are to run a shell under GNU Emacs or screen.

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Ross Boswell

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Dec 5, 1993, 2:17:48 PM12/5/93
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Laszlo Herczeg (l...@whome.uucp) wrote:
: What would it take to implement scroll-back on tty output?

: That is, the user could scroll back on the screen output by hitting
: a certain key, such as PgUp.

No problem at all -- just hit Shift/Page-Up and watch it happen!

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Frank Lofaro

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Dec 5, 1993, 6:39:10 PM12/5/93
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In article <126...@hydra.gatech.EDU> gt8...@prism.gatech.EDU (Robert Sanders) writes:
>
>A more complete implementation could be put in the kernel, but I'm
^^^

>not sure the benefits would be worth the bloat. I can usually get
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>the same effects using pagers when I need scrollback. Other
>approaches are to run a shell under GNU Emacs or screen.
>

Follow-ups to comp.os.linux.misc.

Ouch!!!!!!!!! That means that if someone decides to implement it, there will
people rallying against it?! I sure hope not! Maybe make something like that
configurable.

I don't like to see development discouraged.

I myself and a friend have quite a few things we would like to see in Linux.
Things like raw devices, async I/O, etc, etc. Things that would make Linux
a more complete operating system. We (and other contributers), would be
willing to implement stuff ourselves, but certainly not if it isn't going to
be in the main kernel distribution.

Hacking something into a kernel to get a feature I need is acceptable.

(I am willing to implement features I need/want. I am not going to just sit
back and whine and do nothing useful. I can understand developers frustration
at those type of users.)

But:

Hacking something into every kernel that comes out to get a feature I need is
_NOT_ acceptable!

In other words, please give us small-time developers a chance to contribute.
It will make us all much happier and Linux much better. If it works, let it
go into the kernel, unless there is a _very_ compelling reason to do
otherwise. If it is questionable, just put a config option to enable it.

This is _NOT_ a flame, merely a suggestion.

Follow-ups to comp.os.linux.misc.


Matthew J. Ryan

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Dec 5, 1993, 10:10:37 PM12/5/93
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In article <1993Dec6....@nehlsen.toppoint.de>,
Stefan Nehlsen <ste...@nehlsen.toppoint.de> wrote:

>bos...@chem.canterbury.ac.nz (Ross Boswell) writes:
>
>>Laszlo Herczeg (l...@whome.uucp) wrote:
>>: What would it take to implement scroll-back on tty output?
>>: That is, the user could scroll back on the screen output by hitting
>>: a certain key, such as PgUp.
>
>>No problem at all -- just hit Shift/Page-Up and watch it happen!
>
>Nobody told me, I think 99% of all Linux users don't know this!
>
Hmm...Is this little lifesaver documented anywhere (other than the
source :) ) And are there any other interesting keyboard controls
like it? I took a quick look through my documentation collection,
didn't see it, though I might have overlooked it....

- Matt

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Matthew Ryan
rya...@rpi.edu

Stefan Nehlsen

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Dec 5, 1993, 8:11:54 PM12/5/93
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bos...@chem.canterbury.ac.nz (Ross Boswell) writes:

>Laszlo Herczeg (l...@whome.uucp) wrote:
>: What would it take to implement scroll-back on tty output?
>: That is, the user could scroll back on the screen output by hitting
>: a certain key, such as PgUp.

>No problem at all -- just hit Shift/Page-Up and watch it happen!

Nobody told me, I think 99% of all Linux users don't know this!

bye Stefan

--

Stefan Nehlsen ne...@toppoint.de


Matthias Urlichs

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Dec 6, 1993, 3:48:35 PM12/6/93
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Speaking about lifesavers... what I'd like to have is a "Stop" button which
halts the machine if the console runs off on me. (It's pretty hard to read
anything when several screenfuls per second just zip through.)

I've thought of adding an external NMI button, by simply connecting
a pushbutton to the IOCHK bus line and to ground. However, Linux seems to be
turning that particular feature off:
- Linux recognizes NMIs which are generated by parity errors.
- The BIOS thinks there was a parity error when said button is pressed.
- However, as soon as Linux boots, the button does nothing.
(OK, it clicks reassuringly. ;-)

Conclusion: Something turns off the IOCHK line. Where, how?

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Robert E. Wyrick

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Dec 17, 1993, 2:58:39 PM12/17/93
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Matthias Urlichs (url...@smurf.sub.org) wrote:
: Speaking about lifesavers... what I'd like to have is a "Stop" button which

Ctrl-S (^S) always works fine for me. Followed by ^Q to resume.

Rob

Fritz Ganter

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Dec 19, 1993, 9:18:08 AM12/19/93
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Robert E. Wyrick (wyrickre@wyrickre) wrote:

Or better: use Scroll-look, and any key (also Scroll-lock)
resumes. And you have also a light which indicates the scroll-status.

: Rob

Fritz

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Matthias Urlichs

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Dec 24, 1993, 6:25:55 AM12/24/93
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In comp.os.linux.development, article <2et31f$d...@master.cs.rose-hulman.edu>,

wyrickre@wyrickre (Robert E. Wyrick) writes:
> Matthias Urlichs (url...@smurf.sub.org) wrote:
> : Speaking about lifesavers... what I'd like to have is a "Stop" button which
> : halts the machine if the console runs off on me. (It's pretty hard to read
> : anything when several screenfuls per second just zip through.)
>
> Ctrl-S (^S) always works fine for me. Followed by ^Q to resume.

Flow control doesn't (and can't be made to) work for console output from
within the kernel.

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