Michael Black formulerede lørdag:
On Sat, 31 Aug 2013, John G wrote:

William Sommerwerck explained on 30/08/2013 :
As far as I know, no monitor can be damaged by yanking the input signal.
So the "burp" while switching shouldn't be a problem.

The only way that I know of that a monitor can be damaged is if it's a
multi-sync model, and it's driven at a scan rate above its highest spec'd
rate. Other than that...

I know this is OLD History but-
The early text only green IBM PC monitors needed a sync pulse from the CPU
or they would "self destruct"
The monitor was powered from the CPU power switch so that it cold not be
left on alone.
Of course that is really long ago history. ^^

That sounds more like legend. I had a couple of Ball Brother open frame
small monitors that I used back then, for my OSI Superboard and then my Radio
Shack Color Computer. They needed a horizontal sync signal to generate the
horizontal ramp (and the very high voltage), but if there was no horizontal
sync signal, nothing bad could happen.

Michael

I once had an *old* tube TV-monitor (from a TV station control room).

I had it connected to a Sinclair ZX-81, which use the CPU for also
generation the video signal.

The ZX-81 could be put in "Fast" mode, where it used all the CPU-time
for computing instead of video generation, so the video was not proper
synchronized.

This unsynchronized signal probably had a higher flyback frequency or
something, causing the high voltage to go bananas, so sparks flew,
which produced large bangs from inside the monitor.

When the monitor finally died, it got replaced with a B/W tv, where I
cut a trace from the tuner and applied the video signal to the pcb.

This ZX-81 later got fitted into a rack, with a wirewrapped 64Kb
expansion ram and 6 channel audio. Even later, the CPU lived on in a
CP/M-plus system with a whopping 3/4 MB ram. But that's another story.

Leif


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