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- Path: ks.MI.Uni-Koeln.DE!kluebke
- From: kluebke@mi.uni-koeln.de (Shep)
- Newsgroups: comp.sys.amiga.hardware
- Subject: Re: How to calculate monitors frequencies, help
- Date: Fri, 9 Feb 1996 10:22:22 GMT
- Organization: Back Room Boys
- Message-ID: <kluebke.11.823861342@mi.uni-koeln.de>
- NNTP-Posting-Host: ks.mi.uni-koeln.de
-
- uljff3@guest.arnes.si (Jernej Pecjak) wrote:
-
- >Subject: How to calculate monitors frequencies, help
- >Date: 7 Feb 1996 14:28:04 GMT
-
-
- >I am confused. What is the formula in horizontal and vertical resolution
- >for amonitor. Well, let me tell an example. I have a NEC 3D with hor. fre
- >of 15.5 -38Khz (goes to 40 BTW) and vertical from 50-90Hz. If I want
- >resolution of800X600 (colours do not matter if I am right), how fast
- >refresh will I get onthis monitor? There must be some connection and some
- >formula to calculate this.Another specification is the 45Mhz of bandwidth
- >of the monitor. Does this haveany connection? Could I have 800X600 in 70Hz
- >or not? How to calculate thismyself? In monitor there is specification that
- >I can have 1024X768 ininterlaced. Why interlaced? How about 800X600. Will
- >there be interlace also?
-
- 1) *Horizontal* resolution is unimportant for the horizontal frequency
- (although that may sound odd), so are colors.
- 2) Horizontal Frequency (that's the 15.5 - 38 KHz range you mentioned)
- is calculated as
- vertical resolution * refresh rate (+ 5%, to be exact)
- So, let's make a test:
- 800x600 in 70 Hz is...
- 600 * 70 Hz = 42Khz (44 Khz, if you add 5%).
- So this resolution/refresh rate combination is above your monitor's
- maximum of 38 Khz so you can't display that.
- You might get a refresh rate of about 65 Hz, though.
- 3) 1024x768 interlaced means that any (again: vertical) resolution of
- 768 points or more will automatically be displayed in interlace
- (i.e. in half the refresh rate).
- So, since your monitor does 38KHz, you can get about 50Hz refresh rate
- which will be displayed as 25Hz interlace - just like Hires 640x512... :-(
- 800x600 works noninterlaced, since 600 < 768.
- So you can think of 1024x768 as a *theoretical* maximum resolution.
- (Of course, you can display 1280x1024 also, but the monitor's dot pitch
- - which is, if I'm right, about 0.30mm - will not be enough to get a
- sharp image).
- Today's monitor's have gotten rid of the interlaced modi at all.
-
- 4) As for bandwidth, sorry, dunno about that...
-
- Shep
-
- -----------------------------------------------------------------------------
- Kai Lübke
- Mathematical Institute
- University of Cologne
- Home: Amiga 2ooo, 1MB, A1o81, NEC P6+
- Home: Amiga 4oooT, 1oMB, 1GB-HD, Cybervision64 (soon)
- Office: Pentium 9o, 8MB, 540MB-HD, Miro 1764 :-(
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-