Reply 20 of 29, by jal
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wrote:wrote:Drawing the screen, especially a graphics screen, takes quite some time, since the internal buffers have to be converted to output suitable for your display configuration. I'm quite sure DOSemu does this as well.
Is it because DOSBox updates the screen continously, while other emulators, including DOSEmu, only update the screen when necessary. Continously updating the screen would definitely take a lot of CPU time, notice what happens when you keep scrolling the scrollbar up and down.
I'm pretty sure all emulators update the screen continuously, as it is very unusual for the screen not to be changed at all during a long period of time. Escpecially in games, the area DOSbox focusses on, the screen will be updated continuously.
A problem with not updating the screen at all when nothing changes, is that it would be difficult to maintain a constant speed without the emulator feeling irrisponsive or jaggy at times, as the OS has to dedicate variable processor speed and resources to the emulator.
JAL