Use the sdl.dll from 0.65 with 0.70 and see what that does.

Whoops, forgot to note I'd actually done that... (along with SDL_net.dll for good measure)
In any case, it won't start up due to a missing export in the older version.

Entry Point Not Found
The procedure entry point SDL_strlcat could not be located in the dynamic link library SDL.dll.

Do you have an analog gamepad/joystick connected?
Have you tried other SDL apps? Like ScummVM/Qemu/etc...

You mentioned "video related settings". Did you mean output=?

Output, Frameskip, and Scaler, actually.
I do have an analog joystick connected - a USB Sidewinder Precision 2. Sometimes there's also an Xbox 360 controller connected, though not at the moment.
It just crossed my mind to try the NEW SDL with the old DOSBox, and boom - 0.65 exhibits the problem. The official build of 1.2.11.0 from libsdl.org also causes this in both versions of DB.
Wonderful. </sarcasm>

For what it's worth, I also disabled one monitor and it still caused this. I was about to say that DOSBox might not be at fault, except that ScummVM seems to run fine with the official build of 1.2.11.0. I don't have a game to run with it right now, as I'm on dialup and they seem to be a bit large for that to get instantly...but it boots and the interface moves at full speed with no excess CPU usage. Also GLTron and some other random OpenGL/SDL demos I had floating around work on the official SDL binary with no issues.

well dosbox 0.70 tries to force sdl into certain videodrivers.

The SDL.dll from 0.65 isn't compatible with 0.70 or 0.66 as it misses key functions it needs as you saw with the Entry Point Not Found.

The SDL.dll from the SDL site is also quite buggy with some settings. The best thing to do is reinstall 0.70 or use the sdl.dll from ykhwongs DOSBox build.

If you had a Entry Point Not Found the best thing to do is to do a CTRL-ALT-DEL and open up the Taskmanager from Windows. Then kill off the still running DOSBox's. When DOSBox has an Entry Point Not Found error it keeps on running just using up CPU.

I'll put it in the FAQ. Don't know what DOSBox does in Linux when something like a Entry Point Not Found error occurs.

Erik.

*sigh*
First off, the SDL dll from ykhwong's DOSBox compilation caused exactly the same problem.
Next, I dunno if it's just 0.70 or something in my system, but DB didn't stay running in the background after the entry point failures - I checked the process list, twice. And CPU usage was normal.
Since DB seems to be the main SDL application (that I have handy) causing problems, either the others just don't hit the problem point somehow or other, or it's partly DB's fault with Qbix's comment about forcing SDL into certain videodrivers. I guess for the moment I'm going to end back up on 0.65 because as of right now I simply can't use 0.70.
Any further suggestions are welcome, of course. 😒

Boot XP into VGA mode and try it there.

I'm a little confused - what exactly do you have in mind? Safe mode - or using the compatibility option to drop the resolution on execute? Safe mode's usually higher res than normal VGA though for me.
I did go ahead and test the compatibility options - didn't change anything.

Yes think he means safe mode.
Also try different drivers for your graphics card and then
re-test all output= modes.
And remove all joysticks/other input devices besides mouse/keyboard.

If you press F8 before XP boots you should enter the boot menu where you can boot into VGA mode (uses XP vga.sys to access VESA bios of your card) or you can enter safe mode which will do the same thing.

I just mentioned VGA mode instead of safe mode because the only difference between VGA mode and normal boot is that your are using vga.sys, whereas when you boot into Safe Mode, alot of other drivers and software will not load.

Hm. I never noticed/remembered the VGA mode on that screen. Never did use it as I needed safe mode when I start that. I'll give it a shot later on today.
Regarding the video drivers, I'm using the current ForceWare set (93.71) and have had no other issues with them. Reinstalling them might cause whatever's tripping DB up to get reset though, so it's worth a shot. (Still strikes me as something should be a little more flexible if that's the case, though)
It'll have to wait until I'm not busy (due to the reboots involved) but I'll fiddle with it. Thanks for the ideas, even if they end up not helping in the end. 🤣

I know it's been a while since I last posted (in DosBox General) about my issues with DosBox 0.70.. and I just wanted to make sure that I'd at least let people know what happened. I've completely reinstalled my video drivers (including a version or two back) and the like, and nothing changed. I tested in VGA mode during this and DB refused to start at all while there, much less cause the rampant CPU usage and slowdown problem. I did go back to the newest drivers after that, for the record.

I'll be using 0.65 for now (it works great!) but I honestly would suggest looking at what you're doing with SDL, as from the earlier tests and statements it sounded that it may have been a combination of your settings and a possible bug you mentioned in SDL - which isn't your realm. I'm no expert on DosBox or SDL, of course... I could be way off base in my guesses here. In any case, I'd hope it could be bypassed with a different way of handling the video. I have no idea how, sorry, just that other SDL apps don't exhibit this on the same SDL release. 🙁
I'm willing to test and help supply debug data as to what's going on if someone wants to take some time and give it a look. Just PM me, I think.

Hopefully I'll be able to run the next release without problems. Keep up the good work - without you it wouldn't be around at all! 😁