es1@cunixb.cc.columbia.edu (Ethan Solomita) (07/14/90)
Just a little quirk about the A3000 that happens to me and someone else as well. The left half of the top scan line on the screen flickers. It is only one scan line, so it seems very wierd. Any explanation or way to stop it? It isn't the monitor, since I've moved the image around on the screen and it is still there. I've also used the same cable on my A2000 without problem. -- Ethan Ethan Solomita: es1@cunixb.cc.columbia.edu "If Commodore had to market sushi they'd call it `raw cold fish'" -- The Bandito, inevitably stolen from someone else
visinfo@ethz.UUCP (VISINFO c/o Sascha Schnapka) (07/17/90)
In article <1990Jul14.043408.20134@cunixf.cc.columbia.edu> es1@cunixb.cc.columbia.edu (Ethan Solomita) writes: > > Just a little quirk about the A3000 that happens to me >and someone else as well. The left half of the top scan line on >the screen flickers. It is only one scan line, so it seems very >wierd. Any explanation or way to stop it? It isn't the monitor, >since I've moved the image around on the screen and it is still >there. I've also used the same cable on my A2000 without problem. Every Amiga 3000 i've seen had this flicker in first line. I suppose that's a "feature" of the display enhancer. It looks like the display enhancer is turned off in the first line and that it has to check wether it has to deinterlace or scan double. Could someone at Commodore confirm this? You can only stop it if you disable interlace or if you open a productivity screen. /* -------------------------- SG (Simeon Graphics) ---------------------- */ /* Peter Simeon, UUCP: | // // */ /* visinfo@bernina.ethz.ch | // Long live the AMIGA! // */ /* BIX: hardwiz | \X/ \X/ */ /* ---------------------------------------------------------------------- */
hood@cbmvax.commodore.com (Scott Hood) (07/18/90)
In article <5144@ethz.UUCP> visinfo@bernina.ethz.ch.UUCP (VISINFO c/o Peter Simeon) writes: >In article <1990Jul14.043408.20134@cunixf.cc.columbia.edu> es1@cunixb.cc.columbia.edu (Ethan Solomita) writes: >> >> Just a little quirk about the A3000 that happens to me >>and someone else as well. The left half of the top scan line on >>the screen flickers. It is only one scan line, so it seems very >>wierd. Any explanation or way to stop it? It isn't the monitor, >>since I've moved the image around on the screen and it is still >>there. I've also used the same cable on my A2000 without problem. > >Every Amiga 3000 i've seen had this flicker in first line. I suppose that's >a "feature" of the display enhancer. It looks like the display enhancer >is turned off in the first line and that it has to check wether it has >to deinterlace or scan double. Could someone at Commodore confirm this? > >You can only stop it if you disable interlace or if you open a productivity >screen. > This is due to how the current Amber chip does the de-interlace function. On 1950 monitors which allow the user to put the black borders behind the bezal of the monitor, the user will never see this video artifact. On other multiscan monitors that don't allow the user to adjust the size of the screen this top line is visible. It is only present when de-interlacing the Amiga's interlaced display modes. Scott -- -- Scott Hood, Hardware Design Engineer (A3000 Crew), Commodore-Amiga, Inc. {uunet|pyramid|rutgers}!cbmvax!hood hood@cbmvax.cbm.commodore.com "The views expressed here are not necessarily those of my employer!"
bryan@cs.utexas.edu (Bryan Bayerdorffer @ Wit's End) (07/18/90)
In article <13260@cbmvax.commodore.com> hood@cbmvax (Scott Hood) writes:
[about flickering first line on A3000 interlaced display]
=-
=-This is due to how the current Amber chip does the de-interlace
=-function. On 1950 monitors which allow the user to put the black
=-borders behind the bezal of the monitor, the user will never see this
=-video artifact. On other multiscan monitors that don't allow the user
=-to adjust the size of the screen this top line is visible. It is only
=-present when de-interlacing the Amiga's interlaced display modes.
=-
There are two minor problems with this. First, an overscan screen can
begin on this flickering scan line, so if you want to hide the flicker you have
to lose at least one line of overscan. Big deal. However, when the screen is
stretched vertically on the 1950 to hide the flicker, one has to choose between
losing the corners of the display behind the rounded CRT mask and using less
horizontal overscan. Since the 1950 has no (external, at least) analog size
control, a display using full horizontal overscan can't be squeezed just that
little bit needed to clear the corners.
Essentially it boils down to a choice between using full overscan and
putting up with that maddening flicker. It's not such a big deal, though,
since one can just buy a different monitor with a rectangular mask. Given that
the 1950's colors and dot pitch are so, well, mediocre, that's not a bad idea
anyway.
What was the technical reason for not eliminating this flicker?
Presumably it has nothing to do with the requirements of multifrequency
monitors, since the flickerFixer does not exhibit this behavior.navas@sim.berkeley.edu (David C. Navas) (07/18/90)
>On 1950 monitors which allow the user to put the black borders >under the bezel... Hmmm, I'd have bought the 1950 except that the corners seem to gray out, and it's not a very "straight" picture (It curves out at the corners as well) Does anyone know some really *good* multisyncs that would show most (if not all) of the new Denise display (ie. flicker) as well as the Display Enhancer output? -Dave
cmm1@cunixa.cc.columbia.edu (Christopher M Mauritz) (07/19/90)
In article <24951@snow-white.udel.EDU> navas@sim.berkeley.edu (David C. Navas) writes: >>On 1950 monitors which allow the user to put the black borders >>under the bezel... > > >Hmmm, I'd have bought the 1950 except that the corners seem to gray out, and >it's not a very "straight" picture (It curves out at the corners as well) > >Does anyone know some really *good* multisyncs that would show most (if not all) >of the new Denise display (ie. flicker) as well as the Display Enhancer output? I've been giving the NEC 4D multisync a close look. It is a little pricey at $1K, but the colors seem bright, there isn't any noticible distortion around the edges and the screen is larger than the 3D or CBM 1905. > > -Dave Chris ------------------------------+--------------------------- Chris Mauritz |Donde hay una cerveza cmm1@cunixa.cc.columbia.edu |hay un plan. (c)All rights reserved. | Send flames to /dev/null |El Guerrero Aereo es el rey! ------------------------------+---------------------------
klien%ocf.Berkeley.EDU@lilac.berkeley.edu (Karen Lien) (07/20/90)
>I've been giving the NEC 4D multisync a close look...
Funny, I just read an article in Computer Currents that says about the same
thing. I've gotten another letter from somebody who liked the Zenith, but
I haven't been impressed with the convergence I've seen on the models I've
looked at. Worse than my 1311 is now, and that's getting pretty bad, wha
with all the switching between PAL and NTSC I do :) [And the fact that it is
three years old]
Thanks.
-Dave