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From: phil@brahms.amd.com (Phil Ngai)
Newsgroups: comp.os.msdos.misc,comp.sys.ibm.pc.misc,comp.windows.ms
Subject: Re: NEC 3D OK in interlaced 1024 x 768 ??
Keywords: NEC 3D  choice of VGA card
Message-ID: <1990Sep30.061957.28348@amd.com>
Date: 30 Sep 90 06:19:57 GMT
Sender: usenet@amd.com (NNTP Posting)
Organization: Advanced Micro Devices, Inc; Sunnyvale, CA
Lines: 20

In article <1990Sep29.200049.22028@agate.berkeley.edu> c60c-1gd@e260-3c.berkeley.edu (Joon Song) writes:
|So it takes two vertical passes to refresh the
|entire display.  The reason the display flickers is that the display is
|being refresh at only one-half the rate of a non-interlaced display.

This is sort of true but also misleading. In the PC world, interlace
only comes into play at a resolution of 1024x768.  The non-interlaced
systems generally refresh at a rate of 60 hz. All the interlaced systems
I know about use the 8514 system, which is a frame rate of 43.5 hz
and a field rate of 87 hz.

So here is a case where the interlaced display does NOT refresh at
half the rate of the non-interlaced display, since 43.5 is not
half of 60. I understand what you mean but only because I already
knew what you were trying to say.


--
Phil Ngai, phil@amd.com		{uunet,decwrl,ucbvax}!amdcad!phil
The Sierra Club is trying to stop CA-237 from being made into a freeway.