The setup I and others I remember from the Swedish demo scene used was a mono monitor for coding and a TV set for displaying. In the European world of FM-machines this was accomplished with the mono monitor (of course) connected to the monitor output, and the TV set to the antenna socket. It had the very attractive side effect of automatic switching between the screens depending on the video mode - you just had to start your demo (which replaced the VBL vector and thus the default reset on mode-switch) and the picture immediately switched to the TV when low res was set - and back to the SM124 when hi res was reapplied on exit.
Today, it's getting harder and harder to find TV sets with antenna inputs (and, it seems more machines than just mine have started to suffer from drifting or missing carrier on the RF output anyway) - but it's easy to get high res working (most VGA capable monitors can display hi res and an ST->mono VGA cable is cheap) and in Europe I'd assume ST -> RGB scart is the default option for low and medium res.
The point of this post is that I just got, almost, my old coding environment back*

After having forgotten to make sure I was in the demo code (with the VBL rout replaced) a few times and seeing my machine reset upon me I looked for something I never had to figure out 25 years ago due to using the antenna output instead - whether it's possible to stop the ST from resetting when switching monitor altogether.
Of course there is

Most people probably knew this. For those of you who didn't, I've attached the smallest util I've ever written (the active part of the code is 2 bytes

Update: It might be due to the specifics of my monitor switch, but I just realised that I don't even need to flick the dip switch after having turned off the $46e vector. Just as in the good old days as soon as I start my demo screen (which switches to lo res) the picture is output to the TV through the RGB SCART, and when I exit the screen (switching back to mono) the signal goes to the VGA monitor instead. I'm not only happy but VERY happy

/Troed
*) Yes, I could code on my Mac in Hatari or with a cross compiler and move** code on an SD card between it and the HxC floppy emu - but it takes time. Maybe the CosmoSex with mapped network drives will make it quick enough though.
**) Yes, move to target hw. There's no emulator that understands my code
