Analog Board Design Decisions

[VegaVegas]

I'm new to mister FPGA ecosystem and I don't have one but potentially will in the future. First I'm ruling things out what I will need first- I'm in a definitive need for an analog board or at least 100% proper analog solution as I have lots of CRTs. Also it seems like almost everyone buys analog boards and many people are very hesitant about digital boards and this is explainable- retro gamers are conformists and don't like HD solutions and they really want 100% hardware preservation, that's the whole point. So I was reading stuff and it seems like the latest analog board 6.1 has issues with a lot of CRTs or monitors. Question is- what gives?? Isn't that the whole point to design something that works just right??

It appears like analog board could have more features like SNAC port 2 but there's not enough IO pins. However I also question the design choices- analog and digital boards have SD slot no.2. Why do you even need that?? Also digital board has TOSLINK but I will never use it as I have never even seen a TOSLINK cable in my life...

As far as I can see mister community wants to get rid of the idea of analog board altogether because there is also a direct analog video solution without an addon board whatsoever that goes through the HDMI port. This seems interesting but it's really not "direct", it's not an adapter. It requires a very specific and proprietary HDMI converter. Not only that but people reported severe issues with so many of these adapters as you never know what you're going to get. Someone reported they spent over 100$ and achieved nothing. This has been documented here:
https://github.com/MiSTer-devel/Main_MiSTer/issues/410

If Mister FPGA project is officially going to rely on something so random and so poorly documented then I don't think it's a good idea to invest into it. Because all of that I'm questioning purchasing mister altogether...

[FoxbatStargazer]

Mister covers a *ton* of different systems, many of which used different displays. You got the 240p consoles of course, but we have 400p and 480p computers, vector monitors, handhelds, PAL and NTSC, arcades... I don't know which "issues" you are talking about but you can't expect too many analog displays to handle all of those options, especially without some elbow grease.

The official 6.1 analog board is mainly set up for RGB and component. If you want s-video or composite you need to look at some unofficial boards. There's also an 8-bit color limitation, I think due to the number of GPI/O pins used, but only a handful of cores run up against that limit.

The audio port is both an analog headphone jack and mini TOS-link for optical digital audio. The DAC on the board isn't great so it's typically better to take the TOSlink into an external DAC, but there's still an analog option there if you need it.

The only "movement" I've seen towards the digital board is the playstation and saturn cores, which can take advantage of dual SD-RAM. We are getting a pretty good single SD-RAM version of playstation at least, so I wouldn't rush to the digital board just for that.

Personally I've found being able to output separate analog and HDMI simultaneously very versatile and fun, so I'm more than happy to pay a bit extra for that route. If you love CRTs I would just go that route and stop overthinking it. The analog board was created for devs to debug with first and foremost so some variant of it is always going to be relevant.

[H3ML5XLAXBKU]

retro gamers are conformists and don't like HD solutions and they really want 100% hardware preservation, that's the whole point.

That seems like bold assumption. Personally, as a "retro gamer", I prefer HD solutions and am thankful that MiSTer project has HDMI out of the box and that the team are doing so much to make the experience HD so great. I do not have the space for a CRT and am not sure if I would want to maintain and look after one either. Lack of HDMI was the reason I held off on exploring the MiST project. And, someone can correct me if I am wrong, but I believe that Sorg listed on board HDMI output as reason for developing the MiSTer project on the DE-10 Nano (among other reasons of of course; price, etc.)

You may not agree with the current design of the boards, and that's OK, but it's difficult to please every user when their use case for the project maybe different. In the end, it can only be dictated by the developers and what they require/think is needed. This probably won't align 100% with what you desire, and that is OK too.

As with any project requirements and domain understanding change over time. Past decisions that made sense at the time of implementation may lose their value as new features are understood and developed.

E.g. The second SD card slot is usable by some of the computer cores for loading VHDs, and was required by the initial X68000 core until the recent rewrite. While it maybe not necessary to run any cores now, there are probably people who do take advantage of it still. Should it be removed, what about the people who still use it? What would that require to support two versions of the Analog board?

This could also be said for the whole concept of the Analog IO, which may never have been built in the first place if the possibility of direct analog video was understood at the time.

So with that in mind, yes the idea is to develop something that just works. I would say that MiSTer does just that in most cases. However the project is in constant development and the goals are always evolving and changing. Maybe now isn't the right time for you to "invest" in MiSTer, and that is fine.

[Mr. Encyclopedia]

The audio port is both an analog headphone jack and mini TOS-link for optical digital audio. The DAC on the board isn't great so it's typically better to take the TOSlink into an external DAC, but there's still an analog option there if you need it.

This is another thing I wonder about. We have a lot of amazing hardware designers and builders in our community, it'd be great to see a next-generation analog board with its own DAC, preferably a AG6200 or better, built in. A board like that could use the HDMI out with a jumper board rather than GPIO pins to pass the digital signal, freeing up GPIO for a second RAM or a second SNAC port.

[Newsdee]

It appears like analog board could have more features like SNAC port 2 but there's not enough IO pins. However I also question the design choices- analog and digital boards have SD slot no.2. Why do you even need that?? Also digital board has TOSLINK but I will never use it as I have never even seen a TOSLINK cable in my life...

MiSTer is also a development platform for cores and porting them over. The 2nd SD card is wired directly to the FPGA and facilitates ports of cores from other FPGA systems, which have a similar setup.

As for TOSLINK, it gives better audio than the regular jack without requiring an HDMI splitter. You may not see the point for your own use, but I use it with my MiSTers to connect to external speakers.

I never had issues with MiSTer and CRTs, but I only use the RGB output with them. I believe component out work well too.
The issues I've seen are only fro Composite which the board was not really designed for.

[C-R-T]

The analog board is kind of a legacy product from when Mister hadn’t established itself yet.This is why it has some weird quirks.

And documentation is a real problem in the Mister community, which is its biggest flaw I think. Having to read YouTube comments and forum threads, and even worse - join discord! Just to figure out something that should have been in a read me or on the official page is a real bummer.

[akeley]

As far as I can see mister community wants to get rid of the idea of analog board altogether because there is also a direct analog video solution without an addon board whatsoever that goes through the HDMI port. This seems interesting but it's really not "direct", it's not an adapter. It requires a very specific and proprietary HDMI converter. Not only that but people reported severe issues with so many of these adapters as you never know what you're going to get. Someone reported they spent over 100$ and achieved nothing. This has been documented here:
https://github.com/MiSTer-devel/Main_MiSTer/issues/410

The issue #410 you mention is not really an issue, did you read the last comment? It was a matter of changing composite_sync in the mister.ini.
I've been using a DV dongle for nearly two years now and it works perfectly (been also comparing the output to real hardware on more than 6 active CRTs). It's aIso said that DV has better colour depth. I don't use flat panels and analogue I/O boards are rather expensive - especially now - so I think Direct Video is still a very good option, even if getting a working dongle occasionally might be a case of pot luck.

As for issues with I/O boards themselves, I watch the CRT topics rather closely and it's clear that many of them are caused by incorrect ini settings and/or problems with cables or CRTs. Not all CRT sets are made equal and some might have quirks which cause issues.

We're also working on a dedicated CRT Guide section for the Wiki, so hopefully things will become clearer on this front soon because admittedly finding correct info can be a bit of pain, as it's often buried in comments/posts.

[VegaVegas]

And documentation is a real problem in the Mister community, which is its biggest flaw I think. Having to read YouTube comments and forum threads, and even worse - join discord! Just to figure out something that should have been in a read me or on the official page is a real bummer.

Yes this is probably the best sum up of everything. People engineering Mister and addons really should finish college or at least acknowledge the general rule of providing full documentation. Accessing discord for documentation is probably the biggest LOL but it's still true unfortunately. But discord is a big dead meme anyway. What if you get banned from discord because you offended a moderator because you violated a rule out of 15 billion rules posted on there, leaving you losing access to the hardware documentation altogether??

Also I agree about updating the analog addon board altogether and implementing the right DAC (presumably the aforementioned AG6200/AG6201 or something better) on it seems like a very good idea. However... how would that work? If we were to use the existing VGA port on the top then DAC circuit would go there and no problem. What if we want to implement DAC to HDMI port on DE10-nano?? Is this even mechanically possible to do that??

[akeley]

Yes this is probably the best sum up of everything. People engineering Mister and addons really should finish college or at least acknowledge the general rule of providing full documentation.

This is getting silly. College of what, niche hobby projects? "General rule", decided by whom? Does it really need explaining that MiSTer is not a commercial venture backed by multi-billion capital?

The CRT usage is not the main aim of this project, despite that it's still being thoroughly supported and all the basics of CRT use (and everything else) are already on the wiki. Anybody can edit the wiki so it's up to the users to provide additional info (which, as I said, is something we're trying to do as we speak). I've also never had to join discord, simple forum search did the job in most cases.

[VegaVegas]

This is getting silly. College of what, niche hobby projects? "General rule", decided by whom? Does it really need explaining that MiSTer is not a commercial venture backed by multi-billion capital?

The CRT usage is not the main aim of this project, despite that it's still being thoroughly supported and all the basics of CRT use (and everything else) are already on the wiki. Anybody can edit the wiki so it's up to the users to provide additional info (which, as I said, is something we're trying to do as we speak). I've also never had to join discord, simple forum search did the job in most cases.

Your message contradicts itself and you fail to see the point. Yes mister is an open source project but if anyone designs an addon board or adds some sort of functionality, that's great, thanks for them. However they should document it, they should show full diagrams, parts list and describe the functionality or give any other key information. If you lack any of that then you end up with a mess where all information is all over the place and everyone gets confused. Someone even asked a question about parts list for the official analog board. If you don't provide documentation then you end up with crap like this. You still said forum searches gave you back most of the info but not all of them

[akeley]

If you don't provide documentation then you end up with crap like this.

End up with "crap" like what, exactly? So far you have failed to demostrate it at all, all we got is some complaints about I/O features of a "I don't need them therefore they are pointless" variety and misunderstood git issue.

Serioulsy, mate, perhaps you should get a MiSTer first and see how it behaves in reality, instead of basing your complaints on some internet she-said-he said randomness, which you don't really understand and misinterpret because of your lack of hands-on experience.

You still said forum searches resolved most of your issues but not all of them

Never said that. What I did say is that forum search did the job in most cases. In others it was forum queries, or even just gradual learning from my own experience, in other yet changes to cores (they are WIP, obviously).

Once again, this is a hobby project and nobody has any obligation to provide anything to you on the level of a commercial one, especially seeing as CRT usage is a niche within a niche (even though most of it is explained anyway)

[VegaVegas]

I try to find the info where it said the VGA port currently is fine for using with TVs but is too weak for CRT VGA monitors so direct video workaround is recommended. I believe this info was on an official page but I literally can't find it now and I really want to find it. How do you explain this??

[akeley]

How can I explain something I've never heard about and to my best knowledge simply isn't true? I don't recall ever seeing this on MiSTer's wiki nor hearing about it on the forums. The only advantage Direct Video might have over I/O VGA I know is the colour depth and the disadavntage that it's trickier to use with component.

[VegaVegas]

FOUND IT:

The Analog output on the IO board has some hardware issue which causes lower gain (and thus a dimmer picture), it is not that noticeable (other than on a direct compare) on a SD CRT, but it is very noticeable on a PC CRT or HD CRT.

viewtopic.php?t=340

Actually it wasn't on the official wiki but it was discussed here. Still a few people noticed this and the debate was created

[akeley]

Still a few people noticed this and the debate was created

Yes, and? Did you (again) read the replies in the git isssue mentioned there? There are countless threads here (and elsewhere) where people think there is a problem, which then either gets explained or left as is, because mostly people sort it out themselves (user error). And even if there really is an issue it's up to us to help with solutions, since there is only a handful of devs who are quite busy anyway.

So you're welcome to join, test this particular case and report your findings.

[Kitrinx]

I try to find the info where it said the VGA port currently is fine for using with TVs but is too weak for CRT VGA monitors so direct video workaround is recommended. I believe this info was on an official page but I literally can't find it now and I really want to find it. How do you explain this??

Let me clarify some things for you. Officially, MiSTer supports HDMI output. The analog output has always been considered secondary and optional. That said, almost all cores do their best to attempt to support it as it has become quite an ingrained feature, but the range of outputs goes from the 75hz wonderswan handheld screens to the 55hz x68000 video at 31khz to the crazy resolutions of the mac screens. Trying to make all of these work on a myriad of old displays 15khz and 31khz, rotated and not rotated, spanning from 1980 to 2007 is not a trivial task in the least. Secondly, MiSTer owes a lot its success to its relatively affordable nature, compared to other hardware based solutions (pre pandemic at least). It has grown because of people willing to take a chance on the price. It's easy for a layman to say "lol why don't you just add all the parts to it, so dumb" but in fact, this costs money, it takes up space, it makes the boards harder to build yourself (which is what we did before there were so many sellers) and in the end, there is a cost to value consideration involved.

Direct video was added to try to give people a way to get analog video cheaply, rather than having to buy an IO board. You're welcome that the option exists, it didn't have to, because the guy who added it for free certainly didn't need it. As demand increases for this feature and the project in general, I am sure we'll see more options here.

If you don't like the way it's built, or you don't like the documentation, how about your chip in something to make the project better like we all did instead of just slinging around mud.

On this last point, you will treat the other people on this forum with basic respect, or you will not continue to participate here. Spitting out clearly uninformed insults about things and people who you obviously know nothing about is not acceptable behavior. I hope that's crystal clear.

[VegaVegas]

On this last point, you will treat the other people on this forum with basic respect, or you will not continue to participate here. Spitting out clearly uninformed insults about things and people who you obviously know nothing about is not acceptable behavior. I hope that's crystal clear.

Where was any instance of that happening??

[Xbytez]

On this last point, you will treat the other people on this forum with basic respect, or you will not continue to participate here. Spitting out clearly uninformed insults about things and people who you obviously know nothing about is not acceptable behavior. I hope that's crystal clear.

Where was any instance of that happening??

Please take a few moments and read this thread again and see what you have posted, it is very clear to me and others.

[Xbytez]

I have removed a number of posts in this thread.

Open and frank discussion is fine, disrespect for other forum users is unacceptable. Thread locked.