When using "pause" background priority and "max" cpu cycles, alt-tabbing between DOSBox and some another program (Notepad, etc.) slows DOSBox down. It seems that "max" does not understand "pause". Usually five to ten swaps brings DOSBox to a crawl.
How to reproduce:
1) Use configuration where:
[sdl]
priority=higher,pause
[cpu]
cycles=max
2) Start some computationally intensive game (Elite II: Frontier) in DOSBox.
3) Use alt-tab key combination to jump between the game and some other program. (Notepad, Explorer, etc.)
4) After five to ten swaps DOSBox is really slow.
Workaround:
Do not use "pause" priority:
[sdl]
priority=higher,lower
My personal system:
DOSBox 0.74 (Running "Frontier: Elite 2 (Frontierverse)")
Operating system: Windows XP Pro Service Pack 3
Hardware: Intel Core2 Duo (2.00 Ghz), 2 GB RAM
Thank you for your hard work!
I submitted a patch for it, better late than never. https://sourceforge.net/p/dosbox/patches/285/