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Path: utzoo!linus!decvax!duke!mcnc!unc-c!dya
From: dya@unc-c.UUCP
Newsgroups: net.micro.pc
Subject: Re: rqst for monitor opinions - (nf)
Message-ID: <1215@unc-c.UUCP>
Date: Sat, 28-Jan-84 12:48:01 EST
Article-I.D.: unc-c.1215
Posted: Sat Jan 28 12:48:01 1984
Date-Received: Thu, 9-Feb-84 03:04:19 EST
Lines: 31

References: uiucdcs.4960



       Virtually ALL consumer monitors stink, because their limiting factor
is the dot / other triad pitch. The upper frequency limit can be calculated
by:


       ((line length) / (dot pitch * 51 us) ) * sqrt(2.0)

       Generally, a dot pitch of 0.43 mm is required for satisfactory NTSC
performance on a 15 inch screen, while 0.31 is required for a 13 inch screen
(including luminance to 4.2 mc/s.) Obviously, for RGB this matters because
all three channels have the full video bandwidth.

       Vectrix's monitor isn't so bad ( $ 1100 ) although I don't know if
they will part it out. It has a 0.31 mm dot pitch. There seems to be a big]
brouhaha about someone like MGA which boasts an AWESOME 0.43 dot pitch. (This
is an improvement, my 9 inch ColourTrak is something like 0.8).

       The other limiting factor is how many pixels. If you are only doing 128
by 128, then anything will work. Also, dot pitch is meaningless unless your
monitor manufacturer can guarantee convergence (especially in the corners.)

       Needless to say, the RGB should be direct to the cathodes with a
minimum of amplification, and aperture correction if possible.

--David "Last of the Analog" Anthony

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