nesdev.org

I might as well start by admitting that I'm a novice and an amateur when it comes to these things. Anyhow..

In the documentation for Tim Worthington's NESRGB mod (RGB / S-Video upgrade for Nintendo NES) he mentions the optimal method for transmitting sync information for "obscure video monitors".
"The other sync transmission method is TTL sync. This is mostly used in RGB monitors which were dedicated to a particular task. Arcade monitors, 1980s computer monitors (such as the Commodore 1084 series), and some specialised pro monitors fall into this category."

He also explains how to actually acquire the optimal outcome for this use
"The TTL composite sync (CS#) signal is compatible with systems expecting both composite video sync and TTL sync. I recommend this if you want the best compatibility with obscure video monitors."
"1. Jumper J8 appers only on board V1.4 (NESRGB14) and later. It is for selecting composit sync output type. Open for TTL, short for 75 ohm (recomended)."

I recently remembered that I own one of these obscure video monitors (a Commodore 1084-P VDE PAL) and of course I started wondering how I would actually go about to use my monitor with the NESRGB mod.

Since my monitor doesn't have a scart input I obviously won't be able to use that. So I turned to google, but I can't say that made me totally clear on how to proceed.

Not surprisingly I found out that the are a lot of different input configurations all over the 1084 series. Common among these monitors is that many of these requires (this to me mysterious thing called) Horizontal Sync and Vertical Sync.

Started looking into it, and there is a lot to learn.

I read something about sync striping. Is that the route to take? If so is the case what would be the best practice?

I don't feel like spending money on for example a "OSSC" when I'm not sure if that's what i need.
So if anybody could shed some light and possible explain how to hook up the NESRGB to a 1084 would be truly appreciated.


tl;dr
I want this to plug into this. How do I manage? (image source)
https://gona.mactar.hu/Commodore/monito ... umber.html
https://etim.net.au/nesrgb/installation ... am-NES.pdf

furryNacho wrote: ↑Wed Dec 11, 2019 4:13 pm "The other sync transmission method is TTL sync. This is mostly used in RGB monitors which were dedicated to a particular task. Arcade monitors, 1980s computer monitors (such as the Commodore 1084 series), and some specialised pro monitors fall into this category."

Bare sync signals can come in two versions: video level (~0.3Vpp) and logic level (3-5Vpp). Video level sync signals, as far as I can tell, only really exist in composite sync version: they're the "S" of the CVBS acronym. ("color, video=luma, blanking, and sync")

Composite sync vs separate (H/V) sync is another question. For everything that wasn't a TV, it was so easy to add the one extra wire that there was little advantage on composite sync. VGA has separate sync; Sun and Mac hardware used composite sync, and SGI hardware used Sync-on-green

different input configurations all over the 1084 series. Common among these monitors is that many of these requires (this to me mysterious thing called) Horizontal Sync and Vertical Sync.

Started looking into it, and there is a lot to learn.

"Horizontal sync" only means "move electron beam to left side of screen". "Vertical sync" means "move electron beam to top of screen".

I read something about sync stripping. Is that the route to take? If so is the case what would be the best practice?

It's a little weird to me that the NESRGB doesn't already emit separate sync. I suppose they ran out of pins. But yes, a sync stripper, like the LM1881, would work.

Note that my LCD computer monitors are super pedantic and refuse to draw when given the output of a LM1881 (from an old converter I'd built from PSX to VGA). Old glass things should be fine.

It's a simple enough circuit you could build it yourself out of more mass-market components. But I'm not clear if telling you specifics would be helpful, as opposed to "buy this one inexpensive part and follow the instructions in the datasheet".

Thank you so much for the reply! I will definitely look into the LM1881 solution, sounds promising.