Arcade Monitors
	Vector Monitors So far, I've only been talking about raster monitors These monitors make up an image by scanning electron gun(s) at a constant speed across the display Building up an image one line at a time, and 'sweeping' the guns back between each display line, then finally sweeping the guns back from the bottom right hand corner to the top left hand corner after each complete display cycle During the 80's there were several games that used Vector rather than raster monitors The idea was this : Instead of describing a game's display as a set of bitmaps or sprites, describe the game as a collection of lines
	The main reason for it was economic - High resolution 'raster' displays could not be made cheaply So ,instead, pass the monitor a collection of lines, which would govern the movement of the monitor's electron gun(s),rather than forcing the monitor to use a high horizontal scanrate so it could fit all the 'hires' lines into one display cycle It's like the difference between a normal printer and a printer plotter Vector monitors were troublesome (with cases of a certain manufacture's vector monitors actually catching fire) and they fell out of favour as it became economic to produce medium or hires raster monitors Today, nobody produces any arcade games which use vector monitors The only way to accurately display a vector game is with a vector monitor For instance the 'flicker' option in MAME is designed to emulate the way vector displays were created i.e. vector monitors relied quite heavily on 'after image' That is, they were going through each line to be drawn in the image one at a time and moving the electron gun(s) around the display to draw that individual line So they worked on the basis that the phospors would still 'glow' for a certain amount of time after they were hit by the electron beam Hopefully - every line in the image could be drawn and the 'after glow' of the phosphors would make the image appear stable. Generally, this was not the case and the image would 'flicker' slightly In fact, many vector monitors used long persistence phospors in attempt to reduce flicker This meant that the phospors glowed brighter and for a longer period of time after they were hit by the electron beam than phospors used in a 'normal' monitor Which is why you used to get 'after images' or 'trails' in Asteriods as the rocks moved around the screen and why blowing up the Death Star in Star Wars resulted in such a bright explosion So, displaying a vector game on any raster monitor produces a noticable different result to the original Displaying it on a 15.75kHz arcade monitor with interlacing, automatically introduces a flicker to the display Using a PC monitor, you can run the game at a higher resolution, to try and closer emulate the vector monitor Neither look like exactly like a vector monitor - as nothing does.