Is running 50Hz refresh rate OK for CGA monitors?

[TheManuel]

As I am planning the video setup to finish my arcade maching project using a std resolution arcade monitor, I read how you can set up the monitor to display 288 lines if you set the refresh rate to 50Hz.  This would be for vertical games run horizontally.

My question is, is this a safe mode for the monitor or would that affect its lifespan or otherwise harm it?
Also, the same question for 256/55Hz modes.

Thank you.

[Level42]

How do you think we watched television the last couple of decades in Europe and other parts of the world with 50Hz ?


 

No monitor should have a problem with that, or it's a crap one. (EDIT or a really old one)

[TheManuel]

OK.  Before I dedicate some time to feeling stupid  , I must say that I am aware the PAL standard is 50Hz.  However, I don't know that an arcade monitor's circuitry is the same as a TV which would be a required assumption to then conclude that if it is OK for PAL TV's, then it is OK for an arcade monitor.
It could be that the electronics in a PAL TV are designed to handle 50Hz and an arcade monitor to handle 60Hz.

At any rate, the reason I was concerened is that by going to this mode, are you not over/underclocking your monitor?  I read somewhere this could be risky for the monitor.  Or are you overclocking only if you try to get 288 lines and 60Hz?

Please bear with me.  I am just learning this about stuff.

[ahofle]

All you are doing is adjusting numbers so that a mathematical equation still holds (total # of lines = hfreq / vfreq - 10 or so wasted lines for vertical flyback time).  You are not 'overclocking' anything and have nothing to worry about.  Also, not all arcade games run at 60Hz (there are plenty that run well below such as Mortal Kombat which runs at 53Hz).

[Level42]

Also: most games do run on 60 Hz. Even the one's here in Europe. I use a 9 year old PAL television as a monitor for my Galaxian and so it runs on 60Hz.(which also explains why I always thought those arcade games looked soooooo steady (much less flashy then our 50Hz TV's).
Also, most relatively young TV's (at least here in Europe) support 60Hz to be able to display NTSC material.

There once was a time that the 50Hz/60Hz rate was derived from the mains power. So it mattered if you would run a 60Hz TV in a 50 Hz area (apart from NTSC or PAL). However, already quite long ago, the frame rate of 50 or 60 Hz  is decoupled from that mains frequency and since then there is plenty of range between to let the TV/monitor run on.

About the difference between a TV and a Monitor:
A TV is a monitor with a built-in tuner. That's it, nothing more.
The tuner "receives" the high-frequency radio (or analogue cable) signal and converts it to RGB signals and sync signals. That's where the "monitor" part starts. And that's the same kind of signal that you input into a monitor. That is also why a European TV with a SCART input is exactly as good as a "real" arcade monitor. It completely bypasses the tuner part of the TV.

What monitor are we talking about, the specs could easily point us in the right direction?


(P.S. PAL is not always 50 Hz. There is (was ?) also PAL 60Hz in some countries)

[TheManuel]

Level42:
Please don't interpret my words as meaning I did not trust your statement.  I was merely expalining why I did make the deduction in the first place.  My ignorance is great on this matter.

Amusingly,  I don't have any real monitor to speak off yet.  I simply want to buy one but want to make sure I'll be able to use it successfully on most games that ran on standard resolution.  I was particularly concerened about vertical games run horizontally as implementing a rotating monitor sounds like way too much work and then there are the degaussing issues.  However, running them on a horizontal monitor seems practical if one is willing to use a smaller area of the screen.  There is, of course the issue of having to adjust the vertical size when switching between games but I have an idea on how to handle that quickly:
[url]Post Link[http://forum.arcadecontrols.com/index.php?topic=73180.0/url]

Thank you both for your helpful answers.

[Level42]

Level42:
Please don't interpret my words as meaning I did not trust your statement. 

I didn