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 Post subject: Re: The best way to support VESA BE in long mode?
PostPosted: Mon Nov 08, 2021 8:48 am 
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Ethin wrote:
rdos wrote:
The downside of setting up a fixed mode is that you can no longer use text mode, which is a very fast interface for displaying text. Instead, text mode needs to be emulated with a fixed font, which is much less efficient.

This... Is a very debatable point. Especially considering the fact that every OS uses embedded font rendering in one way or another. I'd say the slowdown isn't even remotely significant, maybe a few hundred ns extra latency, maybe 1-2 us.


Doing repeated scrolls of an 80x25 screen works with impressive speed using text-mode, and you cannot overload it with a normal keyboard repeat rate and decent CPU. If you run the same in real-time with a graphical display, it's easy to overload it even with a very fast CPU. That's why you cannot do the emulation in real-time. Additionally, you also need to emulate the cursor, something that steals time even with no display change at all.


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