That's the overscan area expected to be cropped on a CRT. You could zoom in. Your TV probably has the options too.
If you think that's bad, wait until you see the coloured borders on Mark III/Master System. Or even worse, PAL Master System...
Yeah exactly, that's what I do with my CRT TV. Vertical geometry settings carry over just fine across each system, whereas I have to manually adjust horizontal size and center, according to which console I want to play.
Sometimes I feel tempted by the god-tier IQ you get out of a Framemeister, but there are things (about retrogaming on current displays) that distract me way more than the issues you can experience with old CRTs - say, geometry imperfections, overscan... - and one of them is those atrocious borders. That's why I was wondering if the XRGB-mini could do the trick, and allow you to 'hide' them, without touching the zoom option of your TV.
Oh, and I've seen a PAL Master System straight up running on a full HD monitor. Man, the glare was... Intense.
Yeah, it's quite easy to crop/scale the image however you'd like.
There are even custom profiles that can be loaded on to a Micro SD and loaded into the Framemeister to remove overscan, use 4x or 5x integer scaling, and even crop the picture to remove some vertical scrolling artifacts like can be seen on Super Mario Bros. 3 on the NES, all without having to fiddle with the settings yourself!
Ok, this sounds pretty awesome and interesting.
I'm just curious, so I don't want to waste your/anyone's time, but... Is there any video showing this in action? Something like a before-after kind of comparison?