The State of DACs for the MiSTer and Direct Video

[LamerDeluxe]

Wait for the new official version nine IO boards to be available from reputable sellers like Ultimate MiSTer, MisterFPGA.co.uk, MiSTer Addons etc. They will have 24-bit color output on their VGA connector and good quality analog audio. I will be upgrading my IO board.

But that one won't have USB ports, a power button and most importantly an option to connect with a composite cable

Just get an official USB 2.1 hub board with it and you'll have seven USB ports, again, buy from a reputable MiSTer seller.

For excellent quality composite, get an active VGA to YC/Composite adapter (MikeS1 design), I got mine from RetroCastle. These will work with the native YC signal support that MikeS1 has been building into the MiSTer cores.

[Alf]

For excellent quality composite, get an active VGA to YC/Composite adapter (MikeS1 design), I got mine from RetroCastle. These will work with the native YC signal support that MikeS1 has been building into the MiSTer cores.

Yeah, I'm a little confused about that, maybe you can help me understand.

1.
Why do we need those Y/C cores? Because I have a VGA>composite active adapter from Retroupgrades and it was working fine when I was using a miniPC with CRTemudriver. Isn't this just a signal conversion, why does it depend on the core?

2.
What is the deal with special cables for those Y/C cores? The update script even warns you about it. Can't I just use normal cables?

3.
I tried to hook up my current setup which is the following:
Mister HDMI direct video > simple external DAC (Rankie) to VGA > Retroupgrade's VGA-composite adapter > BVM.
I was using regular cores and the result was a green image
But what bugged me the most was the fact that Mister was reporting 640x240 resolution. I couldn't get the native resolution output. And yes, I did enable direct video in the .ini.

[LamerDeluxe]

For excellent quality composite, get an active VGA to YC/Composite adapter (MikeS1 design), I got mine from RetroCastle. These will work with the native YC signal support that MikeS1 has been building into the MiSTer cores.

Yeah, I'm a little confused about that, maybe you can help me understand.

1.
Why do we need those Y/C cores? Because I have a VGA>composite active adapter from Retroupgrades and it was working fine when I was using a miniPC with CRTemudriver. Isn't this just a signal conversion, why does it depend on the core?

The Y/C cores, which are now just only a few, as most of the official cores have support built-in by now, can output an Y/C signal directly through the VGA port. The cool thing about this is that this signal is very close to what the original hardware generated. For instance, I can see the exact same color patterns in the composite colors that I see in my original Commodore 8-bit machines.

The second advantage is that a VGA to Y/C cable will be a really simple cable and the active composite adapter will also be more simple than converting a VGA signal. The resulting image quality will be better and their is no need to adjust the adapter by hand, to get rid of pixel crawl.

2.
What is the deal with special cables for those Y/C cores? The update script even warns you about it. Can't I just use normal cables?

You need a suitable VGA to component or Y/C cable if you want to use that signal, but if you want to use composite, the active adapter, designed by MikeS1 (who also created the Y/C support in the cores) is the best solution. Any further composite or Y/C cables you might need are just standard ones.

3.
I tried to hook up my current setup which is the following:
Mister HDMI direct video > simple external DAC (Rankie) to VGA > Retroupgrade's VGA-composite adapter > BVM.
I was using regular cores and the result was a green image
But what bugged me the most was the fact that Mister was reporting 640x240 resolution. I couldn't get the native resolution output. And yes, I did enable direct video in the .ini.

I'd expect a VGA to composite adapter to output the right colors, but there is also the composite_sync option in the mister.ini file, not sure if that is needed in this case. For the Y/C cores, you need to also set the right video output type (svideo when using the active adapter), I don't expect that to work in combination with your adapter, but experimenting with it wouldn't break anything.

[Alf]

Thanks. I'm slowly putting pieces together.

Please correct me if I'm wrong on any point here;
So the way I understand is that Mike's Y/C cores have now been implemented into main cores, resulting in the "vga_mode" setting inside the .ini file since you can no longer switch to composite from the core's menu.
However, this only works over the IO board's VGA port and Mike's special VGA-composite adapter. You need both of them to make it work. It does however provide you with native composite signal which is superior to any external DAC money can buy.

But if I wanted a composite signal without using the IO board, I would need an external DAC. Those can come in form of expensive scalers, cheap adapters and even ones built into an IO board. An example of the latter would be Retrocastle's and Antonio's IO boards, both of which have their own DACs built in.

So option 1 is a regular IO board + adapter and option 2 is direct video with external DAC adapter or IO board with a built in DAC.
How worse is the image from DAC, compared to the native output?

If all of above is correct, how does the 24-bit thingy come into play? The current version of the official IO board does not support it and Antonio's built in DAC needs special cores while Retrocastle's IO board does not. So by this logic, the Retrocastle's IO board is currently the best option and I don't need to use their built in DAC, I can simply leave their DIP switches and use Mike's adapter, as if I had an official IO board.

[thorr]

The Antonio board is the same as the official analog IO board from a functionality perspective. It just has better quality components than the older IO board including a better DAC that supports 24 bit color if you use the 24 bit special cores but this is not needed if you don't care about 24 bit. Both have DAC's and these have nothing to do with a scaler. They take the digital signal and covert them to analog but don't scale them. The MiSTer also has a built in scaler that will covert the digital video signal to other resolutions and refresh rates and this new scaled image then either goes out the HDMI digitally or out the DAC to the VGA port. Both outputs can work at the same time too.

[Alf]

The Antonio board is the same as the official analog IO board from a functionality perspective. It just has better quality components than the older IO board including a better DAC that supports 24 bit color if you use the 24 bit special cores but this is not needed if you don't care about 24 bit. Both have DAC's and these have nothing to do with a scaler. They take the digital signal and covert them to analog but don't scale them. The MiSTer also has a built in scaler that will covert the digital video signal to other resolutions and refresh rates and this new scaled image then either goes out the HDMI digitally or out the DAC to the VGA port. Both outputs can work at the same time too.

But am I understanding correctly that Mike's Y/C cores output a native composite signal, therefore bypassing the need of any DAC?

[KennyL]

Y/C still needs signals from vga or dac. Analogue output via vga prot is 18bit from current Sorg's 6.x and older boards for all types of analogue signals (rgb, component, y/c, etc.) Analogue output via direct video hdmi vga dac dongles is 24bit.

Please correct me if wrong, Antonio's board can output 24bit via vga but needs forked cores for 24bit. Retrocastle boards has internal direct video dac that has cable connecting to hdmi port and outputs to vga/saturn port. Saturn port version I think also has internal y/c so you don't need external y/c board. Bad thing is you lose dual analogue/hdmi output. Sorg's new 9.2 board (legacypixels is selling now) has 24bit output via vga (when using analogue addon board) and mister framework is updated to support this. Misteraddon's new analogue pro board has 24bit analogue with internal y/c but I'm not clear if it's using Sorg's new framework or still needs forks (website description looks outdated.)

If you already have a 18bit analogue board, I'd suggest trying PWM builds of psx, n64, and saturn first. Groovy mister has PWM built in.
viewtopic.php?t=7565

[Alf]

Y/C still needs signals from vga or dac. Analogue output via vga prot is 18bit from current Sorg's 6.x and older boards for all types of analogue signals (rgb, component, y/c, etc.) Analogue output via direct video hdmi vga dac dongles is 24bit.

Please correct me if wrong, Antonio's board can output 24bit via vga but needs forked cores for 24bit. Retrocastle boards has internal direct video dac that has cable connecting to hdmi port and outputs to vga/saturn port. Saturn port version I think also has internal y/c so you don't need external y/c board. Bad thing is you lose dual analogue/hdmi output. Sorg's new 9.2 board (legacypixels is selling now) has 24bit output via vga (when using analogue addon board) and mister framework is updated to support this. Misteraddon's new analogue pro board has 24bit analogue with internal y/c but I'm not clear if it's using Sorg's new framework or still needs forks (website description looks outdated.)

If you already have a 18bit analogue board, I'd suggest trying PWM builds of psx, n64, and saturn first. Groovy mister has PWM built in.
viewtopic.php?t=7565

Very informative, thanks.
Just a follow up question, what happens when you want to get composite signal without the IO board with direct video?

Seems like Retrocastle's solution is the best for me personally, with the universal Saturn port, dual RAM option and added USB ports to make the sandwich smaller. Also, the power button and slick case.
However, it does have that darn stock Chinese fan built in, supposed to be pretty loud. That's a deal breaker for me.

[KennyL]

You need HDMI VGA DAC dongle if you don't have analogue io board.

[greenegg]

I ended up getting the moread DAC and I'm happy with it. It had the CS5210 chip.

[akeley]

My old analogue board has stopped responding recently, and I'm using the old AG6200 DAC, so I need a new solution, but I think I'll just get the new official board once there's more choice among trusted sellers. I have also already ordered the RetroCastle Y/C converter.

I have no interest in the special-design boards and DACs, while a good alternative, need another gadget to be able to handle modelines, so that's a serious limitation for me. Not to mention the lottery involved in geting a good one.

[LamerDeluxe]

The Antonio board is the same as the official analog IO board from a functionality perspective. It just has better quality components than the older IO board including a better DAC that supports 24 bit color if you use the 24 bit special cores but this is not needed if you don't care about 24 bit. Both have DAC's and these have nothing to do with a scaler. They take the digital signal and covert them to analog but don't scale them. The MiSTer also has a built in scaler that will covert the digital video signal to other resolutions and refresh rates and this new scaled image then either goes out the HDMI digitally or out the DAC to the VGA port. Both outputs can work at the same time too.

But am I understanding correctly that Mike's Y/C cores output a native composite signal, therefore bypassing the need of any DAC?

They output a native Y/C signal. They active composite adapter makes that into a clean composite signal.

I would wait for the official new IO boards, for 24 bit color and better analog audio, so you won't need specially forked cores. The new boards should be available any day now.

[zazaza]

Does anyone have advice for getting audio to a CRT via when using Direct Video? I have a digital IO board Mister.

I have a powered Moread with audio output, but it has the AG6200 chip. I emailed Moread, and they say the HDMI->VGA DAC with no audio output has CS5210 chip, but the HDMI->VGA DAC with audio output (this is the one I have) uses AG6200 chip.

So, if I get a Moread with CS5210 chip and no audio output, how do I get audio to my CRT? TOSlink? Looking for any help. Thank you.

[dickhardpill]

I use TOSLINK to a DAC because when I was connected to the the 3.5mm jack I got loud pops on startup, shutdown, changing cores.

I purchased this because I live 3 blocks from the store. No noticeable delay in audio.

[zazaza]

Thank you, I'm going to order that one.

Two more questions if I may, please:

1) do I need any further .ini changes to use this audio DAC when outputting to CRT?

2) when outputting to HDTV, does leaving this audio DAC plugged in prevent sound from transmitting through HDMI (so i'll have to unplug the audio DAC from Mister), or can it remain plugged in?

[dickhardpill]

I didn’t need to make any changes to ini files and it does not disrupt HDMI audio.

[zazaza]

Ok thank you for your help. Going to order the parts.

[Alf]

Misteraddon already have the new 2024 model IO board up for sale and so is the official 8.1 board.
Has anyone been able to test them out yet?

[dickhardpill]

I thought the official was up to 9.2? Am I looking at the wrong thing?

https://www.legacypixels.com/mister/index.html

[Alf]

Sorry, my bad. It's 9.2 indeed.
So from what I gather, Misteraddon's IO Direct will offer dual RAM option which is already a win in my book.
But what do we know about the DACs on both?

[akeley]

But what do we know about the DACs on both?

There are some measurements/graphs on the MisterAddons product page: https://misteraddons.com/products/miste ... analog-pro
It seems it's the best at the moment, and I suppose the one LegacyPixels is using won't be far off.

I must admit these new boards left me scratching my head regarding the choice. My old analog board seems to be dead and I'm using AG6200 DV dongle (plus Retrocastle Y/C adapter). I wouldn't mind buying the new analogue IO from MisterAddons - 65 USD seesm a decent price for all-in-one design - but the Saturn DIN is a bit offputing. It means I'd need to buy at least one new SCART cable (not cheap at 35 USD), plus use passthrough one for PVM, and also hope that this kinda setup works fine with all the cores.

Other questions remain: do we also need another set of cables/adapters for Saturn -> composite/Svideo? And what is "USB-C power" for, the whole MiSTer or just the IO + USB board? Is it required?

The alternative is LegacyPixels, similarly priced at 60 USD, and offering a simpler setup with traditional VGA, but no Y/C onboard. So I guess I'll sleep on all this a bit more.

(these are just my observations from brief browse of both of the shop pages, so if I misunderstood something please correct me)

[Alf]

Misteraddon's IO boards will do 24bit on regular cores, this was confirmed to me in a chat with them.

As for the different cables, this one has both RGB and composite combined:
https://misteraddons.com/products/satur ... -universal

But it's currently out of stock, which is exactly what is my biggest fear regarding this Saturn port. Aside from limited availability, I think this solution is great.
The USB-C power, as far as I understand, powers the entire Mister and you have to use it if you install their IO board. Which is fine by me.
Also, this enables you to use one of the 3 buttons for power which is great.

The official one, currently sold by Legacypixels, uses one RAM slot in order to provide analog DAC. Not so happy about that, I much prefer the option to add RAM in the future if needed. I also don't care for simultaneously outputting HDMI and VGA signal so I prefer the Misteraddon's option in this regard.
There is also no "sync on green" switch on the official one, which is a bummer. And I don't see a jumper to switch voltages for the fan, while there is clearly one on the Misteraddon's version.

So overall, I'm leaning towards Misteraddon's Direct IO variant and the only thing concerning me is the availability of the Saturn cable..

edit
Forgot to mention, the Misteraddon's version uses the exterior HDMI bridge which is the price you pay for having a free RAM slot. I don't see a problem with that, doesn't look that bad.

[skooter]

There is also no "sync on green" switch on the official one, which is a bummer. And I don't see a jumper to switch voltages for the fan, while there is clearly one on the Misteraddon's version.

Sync on Green is not needed anymore, it can be set in mister.ini

The jumper to switch fan voltages is on the other side of the board, according to Legaxy Pixels.

I bought the MiSTer 24 Bit I/O Combo but it has not arrived yet.