debs3759 wrote on 2021-06-20, 02:10:

Having recently discovered that I had an EGA monitor that I had forgotten about tucked away in a cupboard I hadn't explored for years, I'm wondering - will it be suitable for testing CGA and monochrome/Hercules cards? Not sure whether I need another, older monitor.

Sorta

EGA will generally support CGA

MDA/Hercules is complicated and may or may not work
Without a specific mention of MDA compatibility I would not just plug it in.

Thanks. Guess I need to find an affordable MDA monitor then. Not sure whether the NEC Monograph System monitor works with MDA cards either, I only know it give 1024 x 1024 mono with the original card (which is in the box with the monitor).

debs3759 wrote on 2021-06-20, 03:00:

Thanks. Guess I need to find an affordable MDA monitor then.

If it is just about testing MDA and CGA cards, and not about period-correct retro operation of that systems, getting a converter like the MCE2VGA or the OSSC might be an easier way that also occupies less space in your home.

On the other hand, if you want to seriously use an MDA or Hercules(-like) card on a CRT monitor, i strongly recommend you getting an original MDA-type or Hercules-type monitor, not a multi-sync one. The refresh rate of MDA/Hercules is 50 Hertz, and on CRTs it's only acceptable if you have a screen with medium-persistence phosphor. Most color monitors (even CGA/MDA/EGA/Super-EGA multi-sync ones that properly sync to MDA) have short-persistence type phosphor which eliminates ghosting, but causes unacceptable flicker with 50 Hz refresh rate.

Side-note: long-persistence type phosphor is used on radar tubes or other displays that update in the range of once a second, and is generally not used in monitor applications.

mkarcher wrote on 2021-06-20, 06:39:

On the other hand, if you want to seriously use an MDA or Hercules(-like) card on a CRT monitor, i strongly recommend you getting an original MDA-type or Hercules-type monitor, not a multi-sync one. The refresh rate of MDA/Hercules is 50 Hertz, and on CRTs it's only acceptable if you have a screen with medium-persistence phosphor. Most color monitors (even CGA/MDA/EGA/Super-EGA multi-sync ones that properly sync to MDA) have short-persistence type phosphor which eliminates ghosting, but causes unacceptable flicker with 50 Hz refresh rate.

tell that to the entire PAL region

flicker is overblown as a problem IMO

maxtherabbit wrote on 2021-06-20, 15:30:

mkarcher wrote on 2021-06-20, 06:39:

The refresh rate of MDA/Hercules is 50 Hertz, and on CRTs it's only acceptable if you have a screen with medium-persistence phosphor.

tell that to the entire PAL region

flicker is overblown as a problem IMO

I won't tell you to have a different oppinion, but at least in this case, I don't think I overblow it.

I experienced the flicker problem on a multi-sync computer monitor first hand. In this case, it's an EIZO 9050 monitor that syncs 15-35kHz and 50 to 90Hz. On a typical eye-screen distance as you use it on computer monitors, I can't stand the picture on MDA reverse video due to excessive flicker. And yes, you are right about the PAL region: I also happen to have an Amstrad CPC at hand that is configured to output PAL. It's perfectly usable with the default color settings (blue background, yellow color), but I immediately get a headache if I reverse the colors.

On the other hand, I also have experience with a dedicated MDA monitor, in this case the Schneider MM12. I could work hours using that monitor, even if some parts of the screen are displayed in reverse video.

I think it's just individual dependent some people are highly bothered by it others are not at all

maxtherabbit wrote on 2021-06-20, 15:30:

mkarcher wrote on 2021-06-20, 06:39:

On the other hand, if you want to seriously use an MDA or Hercules(-like) card on a CRT monitor, i strongly recommend you getting an original MDA-type or Hercules-type monitor, not a multi-sync one. The refresh rate of MDA/Hercules is 50 Hertz, and on CRTs it's only acceptable if you have a screen with medium-persistence phosphor. Most color monitors (even CGA/MDA/EGA/Super-EGA multi-sync ones that properly sync to MDA) have short-persistence type phosphor which eliminates ghosting, but causes unacceptable flicker with 50 Hz refresh rate.

tell that to the entire PAL region

flicker is overblown as a problem IMO

Being from an NTSC region, the last time that I actually got to see 50Hz in action on a CRT TV in continental Europe, I definitely noticed, but found it tolerable . That being said, it was a 13-inch TV . The effect is likely more pronounced on larger screens as peripheral vision is normally more sensitive to flicker, AFAICR .

Incidentally, 100Hz CRT TVs were a thing, likely because 50Hz flicker was a concern to at least some people, even then .

There is also a subjective aspect to it (sample variation between human eyeballs 😉 ) and as such tolerance to flicker varies between individuals .

maxtherabbit wrote on 2021-06-20, 16:24:

I think it's just individual dependent some people are highly bothered by it others are not at all

It think that mighz be the case, yes.
From what I remember, I never noticed flicker on green monitors which were fed with 50Hz PAL signals.
On the other hand, I did notice flicker on oldschool VGA monitors in Windows 3.1 @60Hz at a certain age (teenager time?) .
Nowadays, it again doesn't bother me so much anymore.

Speaking of 100Hz/120Hz TVs..
Perhaps my memories are not correct, but I believe to remember that in the past their picture output
did show some annoying artifacts (lines during fast movemens) sometimes, like it can be seen with poorly rendered DVDs.

mkarcher wrote on 2021-06-20, 06:39:

debs3759 wrote on 2021-06-20, 03:00:

Thanks. Guess I need to find an affordable MDA monitor then.

If it is just about testing MDA and CGA cards, and not about period-correct retro operation of that systems, getting a converter like the MCE2VGA or the OSSC might be an easier way that also occupies less space in your home.

For me it is just about testing the cards. I'll see if I can find one of those adapters..

Jo22 wrote on 2021-06-20, 17:17:

Speaking of 100Hz/120Hz TVs..
Perhaps my memories are not correct, but I believe to remember that in the past their picture output
did show some annoying artifacts (lines during fast movemens) sometimes, like it can be seen with poorly rendered DVDs.

because they used digital scaling

Jo22 wrote on 2021-06-20, 17:17:

It think that mighz be the case, yes. From what I remember, I never noticed flicker on green monitors which were fed with 50Hz P […]
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maxtherabbit wrote on 2021-06-20, 16:24:

I think it's just individual dependent some people are highly bothered by it others are not at all

It think that mighz be the case, yes.
From what I remember, I never noticed flicker on green monitors which were fed with 50Hz PAL signals.
On the other hand, I did notice flicker on oldschool VGA monitors in Windows 3.1 @60Hz at a certain age (teenager time?) .
Nowadays, it again doesn't bother me

Dedicated screens designed for low refresh rates usually had high persistence phosphors

Such screens were easier to damage with screen burn but also would eliminate flicker regardless of how low the refresh rate was
The IBM 5151 was always flicker free due to IBM correctly choosing the phosphor , refresh rate didn’t matter

Me personally I don’t really care about flicker, I ran 1024x768 x87i for decades without issue

Also some EGA screens were MDA compatible and usually had a mono button along with a mention in the owners manual, if you take certain precautions you can just drive an EGA screen with a MDA device and see what happens
Usually you will just loose vhold if it’s too far out of range but I have internally adjusted screens to work with other signals.

Not sure if the op wants to potentially damage a screen

I hate interlaced video, but I can look at 1600x1200p60 all day

maxtherabbit wrote on 2021-06-20, 21:16:

I hate interlaced video, but I can look at 1600x1200p60 all day

Interlaced video is highly dependent on the specific monitor. Back in the 90s, when 1024x768 87i was a common entry-level resolution on CRTs, I had two computers with completely different montiors at that resolution next to each other. On one monitor, the image was just slightly annoying, but you could get used to it. On the monitor next to it, the image was terrible. As I primarily worked in DOS in text mode, and only used Windows occasionally, both computers were usable, though.

mkarcher wrote on 2021-06-21, 06:48:

maxtherabbit wrote on 2021-06-20, 21:16:

I hate interlaced video, but I can look at 1600x1200p60 all day

Interlaced video is highly dependent on the specific monitor. Back in the 90s, when 1024x768 87i was a common entry-level resolution on CRTs, I had two computers with completely different montiors at that resolution next to each other. On one monitor, the image was just slightly annoying, but you could get used to it. On the monitor next to it, the image was terrible. As I primarily worked in DOS in text mode, and only used Windows occasionally, both computers were usable, though.

I would not be surprised if the worse monitor had coarser dot pitch and/or shorter persistence . You wouldn't happen to remember the brands and model numbers ?

darry wrote on 2021-07-01, 23:32:

mkarcher wrote on 2021-06-21, 06:48:

maxtherabbit wrote on 2021-06-20, 21:16:

I hate interlaced video, but I can look at 1600x1200p60 all day

Interlaced video is highly dependent on the specific monitor. Back in the 90s, when 1024x768 87i was a common entry-level resolution on CRTs, I had two computers with completely different montiors at that resolution next to each other. On one monitor, the image was just slightly annoying, but you could get used to it. On the monitor next to it, the image was terrible. As I primarily worked in DOS in text mode, and only used Windows occasionally, both computers were usable, though.

I would not be surprised if the worse monitor had coarser dot pitch and/or shorter persistence . You wouldn't happen to remember the brands and model numbers ?

I'm sorry, I don't remember specific model names. Both were no-name monitors sold by as part of complete PC systems around 1993.

As my issue with the "worse" monitor was an flickery / jittery image, I guess it either had shorter persistence, or it had a sharper beam / finer dot pitch, pronouncing the scan-line effect in 1024x768 interlaced.