Hey guys, I am at my wits end here, so thought I would give this a shot here...

My computer is a laptop with an intel hd 4000. In order to play GOG/dosbox games the way they were intended I purchased an IBM 17" CRT display. I plugged it in, set my GOG/dosbox games to
fullscreen=original
aspect=false
scaler=none
machine=vgaonly
render=surface

And everything looked wonderful fullscreen.

This morning I turned my PC on, started up Anvil of Dawn, and the CRT just showed a garbled screen (as though the res or refresh rate is not supported). Every GOG game shows the same issue, as do all my dosbox games not purchased through GOG.

I changed nothing to cause this to happen, and have no idea what to do. I have tried removing my monitor from device manager, setting it from generic PNP to SVGA, I have run in safe mode and reset refresh rates etc, but nothing seems to work. I even did a system restore to a couple days ago to no avail.

This is driving me nuts because now the only way I can play these games is with aspect=true which messes the graphics up, defeating the purpose of the CRT.

Any ideas??

Only thing that popped into my head is your graphics drivers updating stealthily and a setting needing changed back in your control panel.

I have no real experience with plugging laptops into monitors though. Hopefully someone who does can help you better.

Thank you for the quick reply!
I checked just to be sure, and sadly the drivers do not appear to have updated. Just in case I did a Windows restore, but no luck. Pretty bummed about this. :(

Sorry I can't offer a solution (this is more of a bump in the hope someone else will). Have you tried changing the output mode in the GOG graphics mode setup program?

I'm presuming the display on the CRT is OK when not playing a game i.e. it shows your desktop normally.

Try adjusting your graphics card's GPU scaling setting ([url=http://pcgamingwiki.com/wiki/Glossary:Graphics_card#GPU_scaling]details here[/url]). DOSBox does change the resolution for fullscreen by default so setting the change to be handled by the graphics card rather than the monitor may help here.

Failing that you could try revering to GOG's bundled DOSBox settings since some of those can also affect resolution handling (e.g. fullresolution=desktop makes the game run at the current resolution without switching).

Thanks for all the replies!

I think I have got it!
When I want to play DOS games I need to boot up using the following procedure.

(CRT is off and video cable unplugged)
1) Turn on laptop, wait until Windows desktop is showing
2) Connect CRT monitor
3) Turn monitor on

I have no idea why this makes a difference, but if I leave the CRT plugged in and turned on from the start, it will not work. Windows must be sending some signal to the external monitor during startup to set the refresh rate or possibly resolution mode. Connecting the CRT after Windows has booted for whatever reason works fine.