Subject: Re: Display Problems with kernel 644.

From: Bill Squier <[email-masked]>
Date: Fri, 1 Oct 1993 12:33:00 -0400

>From:	Markus Landgraf <[email-masked]>
>
>   Hi, 
>   vmunix 644 has some problems with the new overscan features on ECS
>   machines. using IRC for example the last two lines get scrambled, the
>   same is for Emacs. Actually they are not really scrambled, but the
>   stuff that scrolls out of the screen on the top comes back on the
>   bottom and scrolls up for another 2 lines.
>   Now I found that when I use kermit to log into my account at Uni I can
>   log in without problems, but as soon as I entered my password the
>   prompt appears in about the middle of the screen, and the same
>   behaviour as with IRC and Emacs occurs, just that the middle of the
>   screen seems to be seen as the bottom, and the stuff that scrolls out
>   of the top of the screen comes back at the bottom and scrolls to the
>   middle where it then disappears.
>   I have no Idea to get the bottom of the display back to the bottom of
>   the physical screen, what I do is I start screen which brings it back
>   down, but procedes in the same way as described for IRC and Emacs.
>
>Good, I'm not the only one with this problem. I reconfigured /etc/termcap 
>and exhibited the tty settings with stty. But the problem with my
>emacs was still there: all is ok until it has to scroll the buffer, then
>emacs tries to put the status line in the middle of the screen. The 
>correct design can restored using ^l. I tried some combinations
>of /etc/termcap entry for a while then gave up. I think this
>is related to the overscan stuff, because I have recompiled my kernel 644
>with option BORING_DEFAULTS. This has to be done, because I have an A2024
>which isn't able to display any overscan.
>

Markus (and others working on this):

This scroll bug is definitely related to defining scrolling regions.
It seems to manifest itself only when the region is FULL SCREEN WIDTH,
but _NOT_ full screen height.  So if you run `window' and set window 1
to about half the screen width and height, you don't see the problem.
Expand the window to fill the full width and do something which causes
it to scroll, and lines scrolled off the top of the screen appear on the
bottom, and continue to scroll until they meet the bottom of the region
of window one.

Hope this helps...

-wps

---

From: [email-masked] (Markus Wild)
Date: Sat, 2 Oct 1993 22:21:06 +0100 (MET)

> bottom, and continue to scroll until they meet the bottom of the region

I tried exactly this, and everything worked as expected. Could someone
other with a Retina console verify the above mentioned bug? I can't
reproduce it... This is for #644.

-Markus
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