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From: acliu@skat.usc.edu (Alex C. Liu)
Newsgroups: comp.sys.cbm
Subject: Re: Desterm 128
Summary: I think is the 1/30s refresh rate
Keywords: I think is the 1/30s refresh rate
Message-ID: <21281@usc.edu>
Date: 18 Nov 89 21:51:53 GMT
Article-I.D.: usc.21281
References: <13190@s.ms.uky.edu> <46400044@uxf.cso.uiuc.edu> <14617@well.UUCP>
Sender: news@usc.edu
Reply-To: acliu@skat.usc.edu (Alex C. Liu)
Organization: Maze Inc.
Lines: 27

In article <14617@well.UUCP> kianusch@unicom.UUCP (Kianusch Sayah-Karadji) writes:
>In article <46400044@uxf.cso.uiuc.edu> djn341@uxf.cso.uiuc.edu writes:
>>   I don't know if a good monitor will make that much of a difference,
>>considering that it trying to cram 50 lines into the VDC's 200 vertical pixel
>>resolution.  That leaves about 4 pixels for vertical resolution which won't
>>be that clear anyway. [...]
>Hmm... That's not correct...
>The way I understand it, the VDC IS able to do 400 vertical pixel-resolution...
>So in 50 line-res, screen does have 8 pixels!
>
>There are even ways to get a 720x700 hi res screen (in interlace)!!!

I think it is nobody's fault.  The VDC chip to achieve that high
resolution uses Interlace mode, meaning, that instead of sending the
same raster image every 1/60s, it alternately sends odd and even
fields of the raster image, with one of them shifted 1/2 raster.  So
it actualy is refreshing the screen at 1/30 s rate.  In some cases
this will not be enough.  I think the Amiga, when uses interlace mode,
also has this flickering.  With, the amiga you can get a flicker
fixer, but with the 128, you will either have to buy a High
persistance monitor, or make a good selection of colors to reduce
flickering...

---
Alex C. Liu 
acliu%skat@usc.edu	acliu@skat.usc.edu
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