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From: stever@videovax.UUCP
Newsgroups: comp.sys.amiga
Subject: Interlaced display flicker
Message-ID: <4216@videovax.Tek.COM>
Date: Mon, 9-Feb-87 16:58:11 EST
Article-I.D.: videovax.4216
Posted: Mon Feb  9 16:58:11 1987
Date-Received: Wed, 11-Feb-87 19:20:33 EST
References: <4047@utcsri.UUCP> <479@linus.UUCP>
Reply-To: stever@videovax.Tek.COM (Steven E. Rice, P.E.)
Organization: Tektronix Television Systems, Beaverton, Oregon
Lines: 39

In article <479@linus.UUCP>, Steven D. Litvintchouk (sdl@linus.UUCP) writes:

> . . .

> On the other hand, the article states that the graphic and sound chips
> for the Amiga 2000 are identical to those on the current Amiga 1000.
> That's too bad.  I was hoping that the Amiga 2000's graphics would at
> least fix the interlace flicker that occurs with 640x400 pixel mode.

> . . .

This issue was discussed quite thoroughly a few months ago, but some facts
obviously need to be repeated now:

     The flicker that is present in interlaced displays is an artifact
     of the NTSC video display standard that was chosen for the Amiga.
     It is not possible to eliminate this flicker without either
     increasing the rate at which the display is scanned or purchasing
     a display with long-persistence phosphors.

     Increasing the rate at which the display is scanned will require
     either that the Amiga output non-NTSC video (which will require a
     new monitor and drastic changes to the Amiga) or that the user
     purchase a display which contains a frame store and converts
     interlaced NTSC video to a progressively-scanned display.  If the
     Amiga were to output non-NTSC video, it could not be recorded on
     a VCR, nor would genlock be feasible.

     Purchasing a new display with a long-persistence phosphor will
     reduce flicker, but cause severe smearing on live video.  If you
     buy a long-persistence display, don't complain about smearing
     when using genlock!

     Changing the chips *will* *not* reduce the flicker.

					Steve Rice

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