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- Xref: sparky comp.os.ms-windows.apps:2461 comp.os.ms-windows.misc:2728
- Newsgroups: comp.os.ms-windows.apps,comp.os.ms-windows.misc
- Path: sparky!uunet!sjsca4!rushmore!poffen
- From: poffen@rushmore (Russ Poffenberger)
- Subject: Re: Wnqvtnet screen scroll is painfully slow
- Message-ID: <1992Sep3.203457.27609@sj.ate.slb.com>
- Sender: news@sj.ate.slb.com
- Organization: Schlumberger Technologies, ATE division, San Jose, Ca.
- X-Newsreader: Tin 1.1 PL4
- References: <715354037.26160@minster.york.ac.uk>
- Date: Thu, 3 Sep 92 20:34:57 GMT
- Lines: 40
-
- ken@minster.york.ac.uk writes:
- : Brett D. Watson (brettw@matt.ksu.ksu.edu) wrote:
- : : >In article <robert.715252601@swanee> robert@swanee.ee.uwa.edu.au (Roberto Togneri) writes:
- : : >>I like winqvt except for one very annoying fact:
- : : >>
- : : >>The screen scroll is interminably slow and painful. Especially when
- : : >>listing a long file.
- : :
- : : But WHY does a simple text window scroll so slow? I have the same
- : : problem as Roberto and I use 1024x768x256. Text in ANY other window
- : : scrolls just fine. And my connection is ethernet so that's fairly
- : : fast. Come to think of it though, if I run a TN3270 window I have the
- : : same problem. What gives?
- :
- : I have a fast local bus S3 graphics card and the scrolling is now tolerable.
- : Under a Trident or Oak or Tseng Labs it's damn awful. Let's face it,
- : WinQVT scrolling is just dreadful: if you use the scroll bar on the side to
- : go back a few lines you'll see it _redraws_ the whole screen for every line.
- : It's just badly written, that's all. Now, if I had access to the TCP (e.g.
- : via a DLL) then I could have done something about it. But I haven't. Which is
- : why I am ditching WinQVTNet and going across to PCNFS 4.0 (beside the fact
- : that PCNFS 4.0 comes with telnet for windows anyway).
-
- Don't be too quick to judge. I have written a comm program, and have to
- wrestle with the problem of Windows slow scrolling and painting, and I
- can assure you that even using the Windows API functions for scrolling a
- client region without repainting is no speed demon either. Accelerator
- cards like the S3 based ones are EXTREMELY fast at video to video BitBlt
- which is what scrolling is, up to 50X faster than a dumb video card where
- the CPU has to read the video memory, shift it, and write it back out.
-
- Face it. When you are talking about a graphics environment, not having
- some help with an accelerated card is going to be slow. Remember that even
- text is still just pixels when writing to the video, not like DOS text mode
- where the card does the text generation.
-
- Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com
- Schlumberger Technologies ATE UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen
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