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F18A MK2


matthew180

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Yup, I have seen that chip many times; it comes up in just about every search I do related to this problem. The main issues with it are cost (is is almost $10), availability (it seems to only be available from DigiKey, and I like to have at least two suppliers for every component I use), and size (the chip is 164-pins and 12mm x 12mm). Unfortunately it tries to do too much. If they would just make a chip for LVDS to DP *or* RGB to DP, that would make it simpler, smaller, and cheaper.

 

I guess the biggest issue is not the cost or the availability but the space? Since you already know most of the boards where the MK2 has to fit, isn't it possible to extend the PCB a little bit at one end?

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As does the Indivision AGA Mk2. It also carries SVGA signalling. The DVI data stream does not carry audio, but can HDMI-compatible audio be injected without interfering with DVI signalling? Is DVI-to-HDMI conversion passive adaptation or is there actual processing?

 

Thanks for pointing out the Sophia. I now want one for my 130XE.

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As does the Indivision AGA Mk2. It also carries SVGA signalling. The DVI data stream does not carry audio, but can HDMI-compatible audio be injected without interfering with DVI signalling? Is DVI-to-HDMI conversion passive adaptation or is there actual processing?

 

Thanks for pointing out the Sophia. I now want one for my 130XE.

 

There are adapters that do just that.

 

https://www.amazon.com/Monoprice-BlackbirdTM-HDMI-Audio-Inserter/dp/B01B5FR7PY/ref=sr_1_3?ie=UTF8&qid=1531107770&sr=8-3&keywords=hdmi+audio+inserter

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Right, I use similar devices regularly, but I am wondering if the F18A Mk2 could put the audio stream into DVI for a passive converter to change the DVI output to HDMI, but still be usable with DVI monitors.

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As does the Indivision AGA Mk2. It also carries SVGA signalling. The DVI data stream does not carry audio, but can HDMI-compatible audio be injected without interfering with DVI signalling? Is DVI-to-HDMI conversion passive adaptation or is there actual processing?

 

Thanks for pointing out the Sophia. I now want one for my 130XE.

DVI-to-HDMI conversion is passive. Nothin' more than changing the plug. Adapters can be had for just a few bucks, and consist of little more than a DVI connector soldered to an HDMI connector.

But audio injection requires active processing, as there is no provision within DVI for carrying audio.

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But audio injection requires active processing, as there is no provision within DVI for carrying audio.

 

Still leaves my question unanswered. Will a DVI monitor ignore the audio stream in the data stream? But then, this is probably a moot question since the source has to negotiate audio connectivity with the sink. And being you can signal from an HDMI source to a DVI sink, I think it stands to reason we could ostensibly offer what is a DVI source that will negotiate HDMI audio if connected to an HDMI sink.

 

With all the hobby developers out there, has anyone considered getting a group together to do an umbrella license of HDMI? Would such a scheme be permitted under the licensing terms? The umbrella could be a non-profit which uses nominal dues and donations to pay the yearly extortion.

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What about just putting a FPC connector on the MK2 and providing a ribbon cable? You can then leave it up to the purchaser to buy the HDMI CYFPV connector for about $5. If you search ebay or amazon with the term "CYFPV" you will quickly find what I am talking about. Since you have nothing but a ribbon cable connector, I would think you would be safe from the whole HDMI issue.

post-64030-0-77085100-1531179311.jpg

Edited by broettger
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What about just putting a FPC connector on the MK2 and providing a ribbon cable? You can then leave it up to the purchaser to buy the HDMI CYFPV connector for about $5. If you search ebay or amazon with the term "CYFPV" you will quickly find what I am talking about. Since you have nothing but a ribbon cable connector, I would think you would be safe from the whole HDMI issue.

 

 

This is not a solution, but it also is. If the adapter card is supplied with the MK18A it is a component, and if the component manufacturer isn't an HDMI licensee (because they're just making components) the final assembler still has to pay the HDMI license fee.

 

However, if he just supplies the MK18A and ribbon cable, and the end user supplies their own FPC to HDMI adapter, he is in the clear and they're not making/selling anything so they are too.

 

This works as a legal solution.

 

As a technical solution, it may work if it can be fitted onto the PCB. That is not for me to decide.

 

This also solves the same problem for *me*... and lets me proceed with a piece of hardware I worked on a couple of eyars ago but did not release for the same reason.

 

Thank you!

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I guess the biggest issue is not the cost or the availability but the space? Since you already know most of the boards where the MK2 has to fit, isn't it possible to extend the PCB a little bit at one end?

 

I really don't want to extend the PCB, since doing that will cause potential problems in some systems. Also, with the MK2 a primary goal is the 40-pin DIP package. Also, that MegaChips IC is 12mm x 12mm, which is almost as big as the FPGA itself, so it would be a very big extension.

 

 

I searched in other forums:

 

Atari 8-bit board, Sophia Rev C 2018, has DVI out:

 

http://atariage.com/forums/topic/274004-sophia-revc-dvi-board/

 

They use a ribbon cable to a board with DVI socket.

 

Thanks for the link, that board is interesting. The part selection seems a little odd though. The Silicon Image IC is about $10, seems hard to find, and only provides parallel-RGB data to DVI conversion. The Altera CPLD is around $20 for just 400-macrocells. At that price you are into a pretty good size FPGA that can easily generate the DVI video directly. I think the creator of the board could reduce some cost and complexity for himself (herself?). For the record, I'm not judging, just making some observations.

 

As for the ribbon cables, I looked at those connectors, they are the Micro-Match series by TE. Although they are small, they are still large compared to the MK2, and I would have to provide both ends of the connection which means designing and building a daughter-board as well. In addition, those connectors can get expensive when you price the pre-made cables plus mating connectors on both ends. Also, on the Sophia board the grounds are missing for the LVDS pairs, which I suppose you can get away with (it seems to be working), but personally I would not omit them and that makes the connector even larger.

 

 

 

Right, I use similar devices regularly, but I am wondering if the F18A Mk2 could put the audio stream into DVI for a passive converter to change the DVI output to HDMI, but still be usable with DVI monitors.

 

Yes, DVI monitors *should* ignore the audio data islands depending on their placement in the data stream. I say "should" because it probably depends on the monitor. The DVI monitor I'm testing with ignores the audio data. The bigger question is, even if I generate DVI video signaling, if I add the audio data islands have I crossed over into license infringement?

 

 

What about just putting a FPC connector on the MK2 and providing a ribbon cable? You can then leave it up to the purchaser to buy the HDMI CYFPV connector for about $5. If you search ebay or amazon with the term "CYFPV" you will quickly find what I am talking about. Since you have nothing but a ribbon cable connector, I would think you would be safe from the whole HDMI issue.

 

Thanks for pointing out those connectors and cables. Because the demand is high for those parts, they are easy to get and cheap, which makes it a possibility to consider this option. The main problem with the FFC / FCP connectors is, yet again, their size. The ones you see on those boards are 15mm wide minimum, and do not fit between the PCB pins of a DIP-40 IC (the DIP-40 pins are 15.2mm (600 mils) on center). However, I can get the connector in a vertical-mount which reduces the size to about 10mm x 4mm, which is still rather wide but possibly workable.

 

This works as a legal solution.

 

As a technical solution, it may work if it can be fitted onto the PCB. That is not for me to decide.

 

That is good to know! I wonder if a USB-C connector also provides the same legal solution? Do you know for certain one way or another?

 

Even though the USB-C connector is also 10mm wide (total PCB footprint), so the same size as the FFC connector for the ribbon-cable solution mentioned above, is does have an advantage of providing a USB-2.0 connection that I might be able to utilize for firmware updates (however that also requires yet another chip). Passive USB-C adapters are also readily available in the market right now.

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That is good to know! I wonder if a USB-C connector also provides the same legal solution? Do you know for certain one way or another?

 

Even though the USB-C connector is also 10mm wide (total PCB footprint), so the same size as the FFC connector for the ribbon-cable solution mentioned above, is does have an advantage of providing a USB-2.0 connection that I might be able to utilize for firmware updates (however that also requires yet another chip). Passive USB-C adapters are also readily available in the market right now.

 

If you provide the cable that has the HDMI connector on it, you're the final integrator and the license fee is still due. If you provide an HDMI output to a ribbon cable, even provide the ribbon cable, but the end user buys a little FPC to HDMI board off Amazon/eBay, you're definitely in the clear. The problem with the USB-C to HDMI adapters is they are active cables. You would probably need to supply them to make sure they were compatible and worked perfectly with your gear. If end users bought them, it would introduce an element of chance you have no control over, but would get the blame for.

 

Now, if you were to buy the simpler ribbon to HDMI connector and one was to accidentally fall into the box.... Oops... *laughs*

 

The FPC size: components can be shifted, but you're still looking at 590 mils for the 15mm wide part. Your ability to host that comes down entirely to your willingness to invest time in redesigning your board - it could be a LOT more dense.

 

What I'm unsure about is whether the FPC out solution has audio lines on it. It's a style of ribbon cable normally used on tablets/older phones/embedded LCDs.

 

IHMO. YMMV. May contain traces of pre-first-coffee-of-the-day nonsense.

 

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If you provide the cable that has the HDMI connector on it, you're the final integrator and the license fee is still due. If you provide an HDMI output to a ribbon cable, even provide the ribbon cable, but the end user buys a little FPC to HDMI board off Amazon/eBay, you're definitely in the clear. The problem with the USB-C to HDMI adapters is they are active cables. You would probably need to supply them to make sure they were compatible and worked perfectly with your gear. If end users bought them, it would introduce an element of chance you have no control over, but would get the blame for.

 

Now, if you were to buy the simpler ribbon to HDMI connector and one was to accidentally fall into the box.... Oops... *laughs*

 

The FPC size: components can be shifted, but you're still looking at 590 mils for the 15mm wide part. Your ability to host that comes down entirely to your willingness to invest time in redesigning your board - it could be a LOT more dense.

 

What I'm unsure about is whether the FPC out solution has audio lines on it. It's a style of ribbon cable normally used on tablets/older phones/embedded LCDs.

 

IHMO. YMMV. May contain traces of pre-first-coffee-of-the-day nonsense.

 

I would say that if he found the correct one that would work on his, and stated a place that it could be obtained, that he would still be clear also. ;)

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I would say that if he found the correct one that would work on his, and stated a place that it could be obtained, that he would still be clear also. ;)

 

 

Unfortunately, as he and I both know, that won't work. Often there will be many almost identical but incompatible versions with the exact same model number. He hopes to sell this for at least 5 and quite probably 10 years or more. He probably doesn't want to do a lifetime buy, when he doesn't know what the market is.

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I would think since he sells everything via a web storefront, that he could get by with selling the mk2, ribbon cables and the hdmi connectors as separate components. If someone buys all 3 components, they are the one assembling and integrating them. The other obvious thing is to provide compatibility with easily obtainable off the shelf parts (aka the hdmi connector) that he doesnt sell, but could recommend where find them.

Edited by broettger
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So I've been doing a bunch of research on the hdmi licensing issue. I think the safest answer is to consult a lawyer, but with that said as hobbyists we are always trying to stumble through things.

Nerdly Pleasures has an interesting article about it.
http://nerdlypleasures.blogspot.com/2017/05/guard-to-hd-nirvana-hdmi-licensing.html

It seems like the main thing to avoid is the HDMI trademark it self. That is the strongest asset they have and is the most straight forward to protect. The other component is the standard it self including the patents that support it. The standard is protected by trademark and patents. The patents belong to various companies participating in the standard. The HDMI Licensing organization offers to become an adopter for $10k a year or for $5k a year with different royalty rates. It's stated that the HDMI license has to be paid by the manufactuerer of the final product. Although they also say that every step in the process should be an adopter as well.

One thing that is interesting is that there are many components that REQUIRE a license before you can even purchase it. https://forum.digikey.com/t/hdcp-and-hdmi-what-why-and-how/784

Another example is the TDA19978A Has the following note on the datasheet. "Use of an NXP IC with HDMI technology in equipment that complies with the HDMI standard requires a license from HDMI Licensing LLC"

I've noticed that many chips don't have this notice at all. I've also seen several 'Display port to HDTV' connectors come when searching for 'Display Port to HDMI'. Amazon also has a Display port to HDMI cable that doesn't have any HDMI branding on it either. I'm inclined to believe that these parts aren't licensed, but is it because they are standing on safe legal ground or because the HDMI Licensing organization has decided not to bother with them. You would think that someone like Amazon would be a tempting target though.

The other odd part of this is DisplayPort it self. DisplayPort has a feature called Dual-mode for Displayport++. It's capable of transmitting both TMDS signals that DVI/HDMI use as well as LVDS signals for displayport. However I assume you don't need an HDMI license for a Dual mode Displayport connector.

Originally I thought I was going to write a good explaination but turns out I'm still confused about it.

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... The problem with the USB-C to HDMI adapters is they are active cables. ...

 

 

Actually is is passive:

 

https://www.hdmi.org/manufacturer/HDMIAltModeUSBTypeC.aspx

 

It is called "Alternate Mode" and DisplayPort has a version as well. USB-C has wires for 4-differential pairs, plus a USB 2.0 connection, power, and a connector-flip detection. There are converter cables available on Amazon.

 

 

 

... The FPC size: components can be shifted, but you're still looking at 590 mils for the 15mm wide part. Your ability to host that comes down entirely to your willingness to invest time in redesigning your board - it could be a LOT more dense. ...

 

 

Actually, the board is pretty dense for the constraints I have to stay within. What you can't see in the posted images are the other layers, the keep-out areas I need to obey follow to maintain signal integrity, and the 1mm spacing between components that the assembly houses specify (and I am pushing that in a few places as it is). This is also only a 4-layer board, and I have a lot of wide paths running around, especially in the area of the SRAM, etc. To properly escape the FPGA I'm using, a 6-layer board is recommended with much smaller traces (5/5 mil is my limit). If I could use via-in-pad, micro-vias, blind and buried vias, 3/3 mil trace/space, etc. then yes, I could certainly pack things in tighter.

 

I have already reworked the board at least twice now, not intentionally mind-you, so reworking the parts of it are apparently not out of the question (I really don't know where my "forget it" point is yet).

 

 

 

... What I'm unsure about is whether the FPC out solution has audio lines on it. It's a style of ribbon cable normally used on tablets/older phones/embedded LCDs. ...

 

 

HDMI does not have physical wires for audio, just the four TMDS pairs. Audio/other auxiliary data is set in packets during the non active video portions of the stream, i.e. it is part of the video stream / protocol. Those CYFPV cables / connectors are just a 1-to-1 mapping of the 19 HDMI signals, which could also be used for DVI.

 

This is the same for USB-C, which is why I was leaning more in that direction.

 

Ether way, I have already decided that obtaining a cable will be an end-user endeavor. The FFP ribbon cable solution has the advantage that is does not add much in the way of length coming out of the end of the MK2. It is small and somewhat delicate though, and wide, and does not provide the potential option for USB update (which may or may not happen anyway, but the ribbon cable precludes it completely).

 

 

So I've been doing a bunch of research on the hdmi licensing issue. I think the safest answer is to consult a lawyer, but with that said as hobbyists we are always trying to stumble through things.

 

...

 

Originally I thought I was going to write a good explaination but turns out I'm still confused about it.

 

Thanks for doing some stumbling, every little bit helps put pieces in place. I'm certainly still confused about some bits too.

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Silly comment, but the articles keep coming back to "the complete end-user product". Wouldn't that be the TI-99/4A with the F18A installed, rather than the F18A component itself? ;)

 

Is the licensing not based around the last party involved in the manufacturing process? It would have been TI if they were selling the 99/4A with the F18A already fitted, but in the current case, it's sounding like it all comes down to you. (And I feel for you - a right PITA that the F18A has got caught up in the licensing issue, but sounds lucky that you found out sooner rather than later.)

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First of all, HDMI is not a singular patent but is a specifications and standards that comprised of multiple active & expired patents. HDMI involves patents that covered DVI including the key patents such as the video transmittion method (TMDS) of ver. 1.0 specifications should be expiring in the next few years. You don't need pay licenses on expired patents.

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First of all, HDMI is not a singular patent but is a specifications and standards that comprised of multiple active & expired patents. HDMI involves patents that covered DVI including the key patents such as the video transmittion method (TMDS) of ver. 1.0 specifications should be expiring in the next few years. You don't need pay licenses on expired patents.

 

 

Great. We should just wait until 2026, when the key patents expire if not renewed for another 14 years!

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