wrexroad wrote on 2021-03-09, 16:36:

Yeah,

but I think that is because the analog side wants the composite sync signal.

Every RGB analog screen I have requires composite sync,

Get that converted and you will have a beautiful 256,000 color pallet display

I wouldn’t try converting to TTL, makes for a sad experience

I have an NEC MultiSync II that works with VGA/EGA/CGA/TTL and apparently had converters that allowed it to work with the Amiga, Commodore 64, and Atari ST as well. To use it with a 15 pin VGA monitor you have a special 9-pin to 15-pin converter, I've always wondered if I should open that up and do pinout/schematic of it since it's a cool thing to have. Might also be asomething standard to use since it seems Mistubishi and Panasonic made similar monitors.

A funny side note, the NEC MultiSync II I have says 800x600 is the top resolution but somehow Seagate Disc Wizard got it up to 1024x768 or so it seems.....fuzzy as heck, but no whine and was still usable like that....kind of shocking in a good way for a CRT from 1988. Had the Horizontal and Vertical position dimed to lower right almost.

creepingnet wrote on 2021-03-09, 18:32:

I have an NEC MultiSync II that works with VGA/EGA/CGA/TTL and apparently had converters that allowed it to work with the Amiga, Commodore 64, and Atari ST as well. To use it with a 15 pin VGA monitor you have a special 9-pin to 15-pin converter, I've always wondered if I should open that up and do pinout/schematic of it since it's a cool thing to have. Might also be asomething standard to use since it seems Mistubishi and Panasonic made similar monitors.

I'd say that either your MultiSync monitor supports analog RGB with separate hsync and vsync or the cable has an integrated XOR gate.
If it can be opened up in a non-destructive way, go ahead and document it. Otherwise, I wouldn't do it.

creepingnet wrote on 2021-03-09, 18:32:

A funny side note, the NEC MultiSync II I have says 800x600 is the top resolution but somehow Seagate Disc Wizard got it up to 1024x768 or so it seems.....fuzzy as heck, but no whine and was still usable like that....kind of shocking in a good way for a CRT from 1988. Had the Horizontal and Vertical position dimed to lower right almost.

The horizontal number of pixels is irrelevant. The monitor doesn't care, but it might be below the actual optical resolution of the picture tube.
The vertical resolution is limited by the combination of highest supported horizontal and lowest supported vertical scan frequency.
This is basically how European SDTV managed to get a higher vertical resolution than American SDTV: By using a refresh rate of 50Hz rather than 60Hz.

Benedikt wrote on 2021-03-09, 19:12:

I'd say that either your MultiSync monitor supports analog RGB with separate hsync and vsync or the cable has an integrated XOR gate.
If it can be opened up in a non-destructive way, go ahead and document it. Otherwise, I wouldn't do it.

It can, it's got one of those old-school project-enclosure style casings that's held on with 4 tiny nut/bolts. My only real concern is the age of the solder inside, though that monitor spends most of it's time connected to a TGA equipped Tandy 1000A.

Benedikt wrote on 2021-03-09, 19:12:

The horizontal number of pixels is irrelevant. The monitor doesn't care, but it might be below the actual optical resolution of the picture tube.
The vertical resolution is limited by the combination of highest supported horizontal and lowest supported vertical scan frequency.
This is basically how European SDTV managed to get a higher vertical resolution than American SDTV: By using a refresh rate of 50Hz rather than 60Hz.

That would explain it. That particular monitor is rather versatile for it's time. I've just heard so many horror stories about damaging older monitors setting them to high resolution graphics modes beyond what's in the manual. I don't have to worry about that with my other three CRTs because they are all mid-late 90's models with a quasi-modern OSD and a way to protect the screen if any specs go too high.