Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!decwrl!lll-winken!sun-barr!newstop!sun!stpeter.Eng.Sun.COM!cmcmanis From: cmcmanis@stpeter.Eng.Sun.COM (Chuck McManis) Newsgroups: comp.sys.amiga Subject: Re: Commodore 1950 Message-ID: <140231@sun.Eng.Sun.COM> Date: 6 Aug 90 18:20:20 GMT References: <7137@helios.TAMU.EDU> Sender: news@sun.Eng.Sun.COM Organization: Sun Microsystems, Mt. View, Ca. Lines: 52 In article <7137@helios.TAMU.EDU> (Duane Fields) writes: >I am about to buy a 3000 and a mistibushi diamondscan monitor. Has anyone >ever used this combination? A friend of mine believes that vga monitors will >always have the little black boarder, and that the 1950 may be a specially >designed system, made to eliminate the border in overscan mode. >Anyone know?? Believe it or not, this message is a milestone for me. It signifies that video display hardware has come full circle, now I believe it shall repeat again. First a little video tidbit : Monitors are made of glass, and glass in not flat. There is a "sweet spot" in the monitor where all the dots being displayed are of uniform size and intensity. The farther from the center of the tube you go, the more difficult it becomes to get uniform pixels. This is due to two reasons. The first is that the glass must begin curving backward so that it can make that sharp turn that defines the "face" of the tube, and secondly as you deflect the electron beam further and further it becomes more difficult to control and begins to hit the phospor at an odd angle making it more difficult to maintain consistent intensity. In 1978 I had a Digital Group 4 board Z80 system with the TVIF interface. This interface was 16 lines of 64 characters on a converted TV set. I _hated_ the fact that the Characters at the beginning and end of the lines were wider than the characters in the center of the screen. I tried everything I could to tighten it up so that all 64 characters would land on the linear region of the tube. I was never completely successful. During those years it became somewhat prestigious to get 64 characters on the screen (or, hold me back, 80 characters) and not have to go into the "yukky overscan region" of the tube. Now, of course, we have people who want to get the "whole" picture and want edge to edge visibility! (Not worrying of course that the pixels on the edge are not linear.) Finally, most video display devices can be adjusted internally to display out to the edges of the screen. Usually there is a "width" slug in the hoizontal output stage that can be tweaked. Changing this can and does void your warranty and a lot of other adjustments usually are tied to this one (changing the width can change the high voltage level which can change the brightness of the beam) Don't open up your monitor unless you are sure you know what you are doing. Otherwise you may just make it worse and end up having to get the entire monitor recalibrated by a service tech. -- --Chuck McManis Sun Microsystems uucp: {anywhere}!sun!cmcmanis BIX: Internet: cmcmanis@Eng.Sun.COM These opinions are my own and no one elses, but you knew that didn't you. "I tell you this parrot is bleeding deceased!"