[dfox]

In this case that probably suffices as there is single intended video source.

Probably all multisync monitors I've seen have actual neon lamps and I believe that these neon lamps are in fact crucial for the "multisyncness", because they provide time for the control electronics (which given the package and pinout seems to usually be 8051) to settle after mode change without blowing out the CRT.

For a long time I've considered all the warnings of the "wrong video mode may damage your display" kind as nonsense. Then about ten years ago I had blown two 12" POS monochrome CRT monitors by unintentionally running them at 1024x768@75Hz, there was correct image for about a second followed by loud bang.

[dfox]

By the way I was thinking about all the multisync monitors I disassembled and got the impression that in all of them horizontal deflection was driven by class D amplifiers (there was half-bridge with switching MOSFETs, IRF640 and such). Does anyone on HN know whether that is correct assumption?

[phire]

Hmm...

If regular CRT televisions behave the same way, that means at some point in time it would have been possible to create a "jamming signal" that transmitted a signal with the wrong refresh rate and blew up all the TVs in the area.

[mjg59]

Regular CRT televisions weren't multisync - at best they'd be able to deal with both 50Hz and 60Hz inputs, but they wouldn't attempt to sync to anything else.

[phire]

Multisync means the CRT will succeed at syncing to multiple specified frequencies.

There is nothing stopping non-multisync monitors (including TVs) from trying to sync to an out of range signal and depending on the design they might damage themselves trying.