HDMI to Old CRT

[abstract3000]

Greetings,

I have a MAME Cabinet built over 20 years ago that used to sport an old PC with a GPU that had S-Video Out to an old Sharp 25" CRT. The HDD was 20GB if that gives you an indication of when it was built, late 90's?

Well the cabinet is in great condition all wired up to an I-Pac and Opti-Pac but has been sitting in Storage and now in my garage with a cover over it for years. I decided this years winter project will be fixing it up and getting it working again. So I'm beginning the Research phase now. I started out buying a Beelink mini PC w/ Windows 11, loaded Hyperspin frontend on it and the specs for the Games I have installed run without any issues so I Would like to continue with the hardware only problem is it has 2 HDMI outputs and no ability to install a GPU.

I had a look over this long thread of information: https://www.aussiearcade.com/topic/76809-a-guide-to-connecting-your-windows-pc-to-an-sd-crt-tv-pvm-or-arcade-monitor/
And from What I gathered I need:
- Groovy Mame
- Tendak AV-107-BK
- crt_emudriver (If even plausible with Windows 11, might have to get te Windows 10 Install)

Though after that point I am going from Digital to VGA, the TV has S-Video Input as well as standard Composite Yellow Input so would prefer the S-Video do I just need a another adapter to move from VGA to S-Video? Is there a particular device that might serve better than others? Or am I way off?

[buttersoft]

Hey there, i've edited the info on converters in that guide as it was a bit out of date, sorry. The Tendak isn't great, i had better results with cheap converters. And someone has been doing a chunk of testing.

https://docs.google.com/spreadsheets/d/1nbepvFFBVsLrs1myOiVWqMVLp9-oB9TataRmVlcyqlA/edit#gid=0
and notes for the above
https://docs.google.com/document/d/1Fz3OfWZgftiTfqG-_JCBJku4a0qzDZeWzmEk4S3Iyjk/edit#heading=h.8c2nlbp9r33g

Ok, so the core of that guide is still solid. To connect to an old CRT TV you need to deliver a 15kHz video mode. Think an SD NTSC/PAL image or close to that. Your PC is not going to be able to output 15kHZ without special tweaking. Sections e) and f) of the guide cover this.

The cheap and simple solution is to go an HDMI-to-AV box for a few dollars from ebay. It'll work, but the results are far from optimal.

I would recommend reading the guide again, from the start, and going over what it says. All I'd be doing is writing out the same things here, but feel free to ask specific questions

After reading the guide you will hopefully be able to say:
- how you intend to get a 15kHz signal (straight from your PC, or via a downscaler/converter?)
- what input signal plugs your CRT has
- how you will get whatever signal type the PC outputs into the TV (just with a cable, or do you need to convert? A downscaler/converter will probably do this, but not always)

Once you have an image on the TV, then, and only then, you think about setting up your emulators.

[Zebidee]

Just like there are many ways to skin a cat, there are many (well, a few) ways to do this.

If it was me, I'd try modding the TV to take RGB input or, failing that, component input.

If soldering irons scare or bewilder you, then you could try using a transcoder to convert RGB to s-video, such as the JROK. Be aware, as Butters has already foreshadowed, some "adapters" are shite. Butters' updated guide should hopefully give you some other tips about quality transcoders.

Then, with a computer and *compatible* video card, you can use Calamity's CRT_emulator driver & software to get 15khz RGB out.

For your old IPAC, you may need to find/download the legacy utility from Ultimarc.com

[abstract3000]

@buttersoft

Thank you for the Links of Adapters, and pointing at the fact the Signal needs to Be sent at 15khz and Stay 15khz, so upon re reading everything a bit closer and further research this is what I have came to understand.

My Beelink with Integrated Intel UHD Graphics isn't going to work with Windows, so that option with Hyperspin is really not a viable option.

Instead it appears I will need to load a Debian Linux distro and possibly a Patched Kernel onto the Beelink and stick with something like Attract Mode instead, to give myself more control over the output of 15Khz.

On top of that due to it being Intel UHD I will have to output a bitclock of at least 25mhz meaning I will need to use Super Scanline configurations but also multiply the horizontal scan lines by like 8 times.

From that point I will need to pick an HDMI to VGA adapter from that list you provided a link too, and from the VGA to the SVideo I will need a Device that passes through the signal rather than trying to convert it to 480i, While I did notice the Jrok adapter people keep discussing that needs the VGA Output to be split into Wires for and pinned RGB to that board which seems a bit messy, whereas this device on eBay https://www.ebay.com/itm/355013147622?hash=item52a86ebbe6:g:Ld4AAOSwlVFk8qvg&amdata=enc%3AAQAIAAAA4GLBB5IugGJLuygkC%2FKtWGAIyXu%2BUqegqVp5rx4bD3Nd22nt9CNL1LxOorVoiQv%2Fm45dsGcssLhcuz3gfToca5g5%2F%2BTOZi9O8F%2FdAJnxpnYQbH9%2FdrAbDW%2FcHcYGG0Gy75tkBSnPkiWz%2Bz8MxYCJv1dXLshyRZvU34qAiHEHbF0mxbKCpbtYXK7viym08UjOGY6rkUnEzZUlildY6B8CqEVxpJVDuAR2Py2kxTg9Uo%2B9lHSJi30askvB57vzAFghTfkS%2FSucdX7yedcF3h0rIuB4L3pxOGmeAqkCB9vkirDW%7Ctkp%3ABk9SR9z1yK3PYg seems like it would serve the purpose and keep everything at 15khz the entire way through?

@Zebidee
I appreciate the Input, but unfortunately it seems the issue takes place before I even get to the CRT in getting the signal to output at 15Khz so I will look into RGB options, I have a very nice soldering Rig in my shop, and feel very comfortable soldering small components, though I do get hesitation around trying to solder individual pins off of an IC Chip.

Though I will consider looking into the CRT Hack for future connections, if this all proves to be too annoying, it might assist in my just throwing in the towel, wiring in a jamma harness and putting in the Game Elf I have had lying around here for years.

[buttersoft]

That item you link to on ebay is a downscaler, with a list of input resolutions and a single, fixed output resolution. It's not a 1:1 converter. The terms VGA and CGA can be a little loose but with that listing VGA is 31kHz, CGA is 15kHz. Sadly the link above was mostly HDMI-to-VGA, nothing much to do with S-video.

I don't know much about linux or getting it running for 15kHz. You might look into Groovyarcade, on the GroovyMAME subforum on here. Substring is the guru for that.

RGB modding is not terribly hard, but like a lot of things it's daunting to start with. There is an excellent thread on the Shmups forum about modding TV's to take RGB input. It's huge and detailed, but all the info you could possibly want is on there. Be prepared to do some reading, and when you know enough to ask specific questions, go ahead

[abstract3000]

So after allot of reading, it simply appears there is no Viable option to Go from the VGA port to the S-video Port keeping the 15khz intact.

I looked over the Sharp CRT I have and since the case was tossed with the manual more than 20 years ago there is no label/Sticker or Printing that indicates the TV's actual Model Number that it was, and every number i get from the board and tube I throw in google and get nothing, so without a way to get ahold of the service manual and layout of the board, I don't intend to go back for an Electrical Engineering degree to reverse engineer the board to wire in RGB Scart plug, I think this is going much further into something I'm simply not that interested or dedicated to as I was 20 years ago when I built it. I am just tired of having a large cabinet sitting around doing nothing.

I decided for the time being going back and doing what I know works, So ordered an older motherboard that accepts the 16GB DDR3 I have sitting around with an i5 Quad Core Chip and PCIe 2.0 Slot on it, To go with an ATI Radeon HD 4890. This way I know the CRT Emudriver is compatible, The card has an Svideo Port to go directly to the CRT and I will just Use Windows 7 Pro with Hyperspin and the MAME set of 800 Games I procured and have everything working I had envisioned. I am not trying to emulate all sorts of systems, just the basic older MAME games, and the Specs on the build are more than adequate to Run.

I appreciate all the input and pointing of resources, as that initial Guide will come in to handy I'm sure when it comes down to passing the connection through, unfortunatley I will just have to put the Beelink aside and put another Caged PC Case below

[buttersoft]

A J-rok will convert Arcade RGBS into S-video, i believe. There are other options too, but it's been too many years since i looked to remember models or even brand names.

A GPU using S-video out does not require crt_emudriver, but it's still a good option, as any official driver is going to be equally ancient and possibly unhappy on modern Windows.

TBH you would want to get a Radeon HD 5000 series card or newer (but still on the crt_emudriver compatibility lists) as the 4000/5000 divide is where newer drivers and EDID emulation kick in. That said, i understand you want an S-video port as a back, which is not unreasonable.

As a last attempt at using this TV for RGB, you might see if there are markings on the two or three largest computer chips inside the TV (on the chassis, which is the common term for the big PCB inside a TV). One of those chips should be the micom, or microcontroller for the on-screen-display (OSD). The other should be the chip you want, generically called the jungle chip, which is the video and scan controller and might show RGB inputs. Normally you get the TV's service manual, which in many cases leads you to googling the jungle chip anyway. If the set is from the late 80's onward, you will almost certainly be able to RGB mod it.

If you're really looking to get something running using the Beeline, you could always go  something like one of these for S-video - https://shorturl.at/aEQV2 and then you go get any cheap HDMI-to-VGA converter if you need to do that. Whether that's going to be any better than a super-cheap HDMI-to-AV box IDK. You might ask on the CRT Collective or other facebook groups about recommendations for a cheap converter.

[abstract3000]

So the Jrok Adapter I assume you are talking about is this: https://www.jrok.com/hardware/RGB.html

Then I would need something like this Cable to go from VGA to that Board https://www.ebay.com/itm/265683088475?hash=item3ddbf2345b:g:8HoAAOSwAiRid~-o&amdata=enc%3AAQAIAAAA8HocyvfvM65WfiZLiMY4M1zbccvNQ2B8Cr6WX51NIXZ%2FkYNZyjSKCVus%2BwB%2FcNpBXe140WQDhyB%2BSjg7aRdNzcu3gbWyr1Ljfq7AE6f6iHIzlzuz8aNtQKf2Jv7%2FHR3s5pdRNRheiprBJ1hd2usY3j8SLzhoDA8i6pmV%2BvuuYf0jr%2BDvEFmNpiI%2Feae4PSzqKjEC1TaZQ%2F2n54T8czsT%2BLEMbzyqDM0EpIr4AnSeSQjfRQTX58S3VrKpFgRzFetYBGhvWrPzqOMDanA427u63bOlQ9Qat4X%2B00MBpFnhDaLYXuD%2Fna2TshfFSpISBUOU6Q%3D%3D%7Ctkp%3ABk9SR_agkJrQYg

And some sort of Plastic terminal to connect the wires in to plug over the pins? That was the only thing that seemed to look like it might work, everywhere else stated that I would need a Transcoder of sorts yet nobody in all the threads I have read was able to name a single one that was still being manufactured.

I dusted off the CRT some more and found a sticker with writing on it and what appears to be a manufacture date and what I think is the model Number 27RS100, I can Find the Manual for Sharp 27RS-100, I have 1 Single long Rectangular IC Chip (I didn't count pins) on the top Side It is: SHARP X3354CEN1 1JDH
on the bottom side of the PCB I found 2 Square IC Chips, Sony CXA20740 & IX3528CE.

I found someone who posted on Reddit about an RGB on a Sharp 27L-S100 (Not sure the difference between the R & the L) posted a Diagram with 2 IC Chip Number neither matched anything I saw on my board and no real pictures of the mod itself so have no clue if it would be the same or not.

[Zebidee]

I looked over the Sharp CRT I have and since the case was tossed with the manual more than 20 years ago there is no label/Sticker or Printing that indicates the TV's actual Model Number that it was, and every number i get from the board and tube I throw in google and get nothing, so without a way to get ahold of the service manual and layout of the board, I don't intend to go back for an Electrical Engineering degree to reverse engineer the board to wire in RGB Scart plug, I think this is going much further into something I'm simply not that interested or dedicated to as I was 20 years ago when I built it. I am just tired of having a large cabinet sitting around doing nothing.

Sharp, like every other TV manufacturer, used the same chassis (with variations) in many different models. There will almost certainly be a manual/schematic out there, you want to identify the chassis model number.

As an intermediate step, try to identify the jungle chip number, then search on that for a datasheet. Jungle chip is usually pretty easy to identify as is usually the largest, and will have video signal inputs and RGB outputs. Then finding the OSD chip should be easy. This, and a good look over the chassis to find where the inputs and outputs are, will give you most of the information you need.

In most cases there will be no need to solder anything directly to a tiny IC leg - there will be more convenient places to hack signals into, like a capacitor or resistor leg or similar on the input line.

Not wanting to disagree with Butters, but I've found that some later model sunset-era (~ late 1990s or 2000+) CRT TVs use large 64-pin jungles with no RGB inputs, and the OSD (on-screen display) functions fully integrated. You can't directly RGB mod these without going directly into the neckboard (but it can be done). I have a bunch of these TVs, but mostly I just component-mod them and then use a GreenAntz VGA RGB-component transcoder (BTW I design/make these, but they don't do svideo).  However, I think that for the early 90's Sharp TVs, inputting RGB via the OSD would likely be the best way to go.

You don't need an EE degree for this stuff. I certainly don't. Just a decent brain and basic electronic knowledge. However, if still reluctant, a more practical option might be to find someone local who can do the RGB mod for you. Try the Facebook groups Butters mentioned.

I decided for the time being going back and doing what I know works, So ordered an older motherboard that accepts the 16GB DDR3 I have sitting around with an i5 Quad Core Chip and PCIe 2.0 Slot on it, To go with an ATI Radeon HD 4890. This way I know the CRT Emudriver is compatible, The card has an Svideo Port to go directly to the CRT and I will just Use Windows 7 Pro with Hyperspin and the MAME set of 800 Games I procured and have everything working I had envisioned. I am not trying to emulate all sorts of systems, just the basic older MAME games, and the Specs on the build are more than adequate to Run.

This is really the best approach, new PC instead or trying to retrofit the Beeline, except I would go for a HD5000+ card as Butters has already suggested. I personally don't believe it is worth pursuing a card with s-video output - the quality will be poor and unsatisfactory. That is not a criticism of svideo, but rather then cards will just squish your video mode into a NTSC standard interlaced mode, probably 720x480i. It is OK for video content (like, showing video or powerpoint slideshow at an education/training workshop), but will be very mediocre for gaming. You would be better off with RGB output from the computer and a transcoder.

If you still want a card with s-video out option, then just buy another card to keep in reserve - they should be cheap enough. The "converter" Butters linked above will also give you svideo, but they are mediocre quality, much like I described above (I have one that is basically identical). Something like a JROK should be better (if your TV does NTSC - an Australian friend of mine recently told me that he tried to use a JROK/svideo with a PAL TV and it simply didn't work  ).

EDIT: I was about to post but then saw your update, so added a little below.

You can make a VGA breakout cable from an old VGA cable.... or buy a new one, should not cost more than $10. I've even used old cables cut off back of old monitors.

Then buy yourself the female headers to plug into the JROK pretty easily:
https://www.ebay.com.au/itm/194389582822?hash=item2d4285a3e6:g:zbgAAOSwql5hTZ34&amdata=enc%3AAQAIAAAA0IU%2B0PWunJ58ET4r7NTOqar6Kw35Ibjb%2FDB8nHzJ0eXT5gXmuDvN7fvEf8OQAjwvvVguClXbIzPssmv3gO9upT5hR%2F0G%2FdBhfUZDIUvmBFesLsM4jo%2FpG%2FYDlDro2jfioSjIbXAoyBN8mkhKF%2FAeasxjJzMWMhamxmcrxyNKR8fgSNU9o6I8T0TjdL1mQdbmfO%2FLkn0KWMOdPGyuxm6FCyxbkT5mMBgOvz%2Fe%2F1b9lLAKMgchgbd5BadLe%2FedD9qgJ4%2BygSatloI0geGr8wAORlA%3D%7Ctkp%3ABk9SR-SxvJvQYg

You can also find those headers available in kits with a bunch of different sizes. This may be a better option:
https://www.ebay.com.au/itm/353414711625?hash=item5249288949:g:MkgAAOSwaRhgR0IU&amdata=enc%3AAQAIAAAA0NygcXeXY6vjpna%2BIMVHGgpHZKLPGpe58Y%2BQQIMla4lSOQbbBQxW3%2FOW708sIuwUHaqgCODCGNiuhpjHm7v52JiJ%2BBSflA9aPUSRziGJ21M7K8o5qJBbwWfgTfBBhComh%2FfheBkgYicmqPX4Pn7WLy0oR0mXOoxzAkRhtVF7sPZoZy5aOjpnGwJMKP7c7eXQ8E3XPyYUtl8pezaRopn7cQXG5%2F0PNkplGIcYM9uPR66kzzUAU5la9a%2Fw7JXwHCJDJDN6WqPGKeoTECPHlF2LUnk%3D%7Ctkp%3ABk9SR6qQqZvQYg

Search for "PCB header connector 6 pin 2.54", and also get yourself a reasonably priced crimping tool.

[Zebidee]

I did some quick googling with the extra info you provided.

According to berrmal64 on this reddit thread, the Sharp X3354CE... jungle is really a rebadged Sanyo LA76843N

Click here is that datasheet.

Someone has already tried modding your model TV on the Shmups RGB mod thread. MarkOzlad (I know him and he knows his stuff) also confirms that is uses a rebadged Sanyo jungle.

You can find a manual/schematic here. It seems like it is just a "supplement", but it has the essential info. I can see the OSD RGB inputs and there is a 5-pin header that you can probably tap into.

I've already attached the jungle datasheet for your convenience, but the schematic was too large.

[buttersoft]

Not wanting to disagree with Butters, but I've found that some later model sunset-era (~ late 1990s or 2000+) CRT TVs use large 64-pin jungles with no RGB inputs, and the OSD (on-screen display) functions fully integrated.

Yeah, that's a point. I have encountered a TV like that, but only one. That said, i'm poor so i have to live in Tasmania, and maybe fewer of those fancy TV's were imported from Victoria

[Zebidee]

Yeah, that's a point. I have encountered a TV like that, but only one. That said, i'm poor so i have to live in Tasmania, and maybe fewer of those fancy TV's were imported from Victoria

May have mostly been for the Asian or developing country market, where the CRT sunset phase lasted a little longer. Most notably the "China TV" chassis and I've also seen similar PCB layouts in other local brands like Toshiba, TCL, Samsung TVs. I've see them a lot in Phillipines, Malaysia, Thailand, Laos, Indonesia, India... to name a few. Often flat screens, but not always.

I can imagine, not many managed to get to Tassie.

Haven't been to all those places on a CRT tour, some I guess, but I have watched an awful lot of repair YT videos for these in Tagalog, Bahasa, Hindi, Thai etc. I do speak Thai/Lao of course, but for the other languages is a lot of guesswork. Tagalog & Bahasa are not too hard to guess at. Almost nothing in English, and when it is the accent is usually so bad I prefer the Tagalog. Fortunately electronics is all the same language, lots of diagrams, pictures and pointing at things helps.

These all-in-one jungles were used in name-brand TVs originally, think Toshiba is the main IC manufacturer but used in sunset Sony, Samsung etc too. From what I've seen.

Anyway, by rolling the OSD (and maybe some other functions) into the one jungle they saved a few dollars. It is essentially a little CPU and the BIOS is stored on a smaller EEPROM chip nearby. You can even re-program the BIOS if you want (I hacked mine to float "GREENANTZ" across the screen instead of the TV brand name) and the service mode is very useful. The chassis's are relatively simple. I think it all came down to reducing costs. In the case of the "China TV" chassis, they are often used with donor tubes to save costs even more. Where do you think all our electronic recycling was going when were shipping it all to China for decades? You can still buy back "new" CRT TVs with a truly new "China TV" chassis and a refurbished tube on Alibaba.com. If you're really lucky the tube might have originally come from your Grandad's old TV.

Anyways, all a bit off-topic, @Abstract's early 1990's Sony appears to have RGB injection via OSD available.

[abstract3000]

Thanks Zebidee for all that info, If nothing else it gives me a Place to Start and a couple individuals who might be able to assist along the way. I did however notice the  Service doc you posted I don't think applies to my TV, I have a 27R-S100 & that manual covers a 25R-S100 ? (maybe they are the same...) I will have to disconnect and dust the PCB off an take a look. I did however see a couple YT videos describing the theory in graphical representation that helped a bit, but we will see How it goes. I tried searching to see if there were any modders providing the service that I could pack the PCB up and ship it too, but that appeared to be a no go, maybe not searching hard enough.

In the meantime from a few different threads from the last couple years I saw and no response from my email,  it appears the Jrok adapters are no longer being made. I found what appears to be similar to a clone in Australia https://www.converters.tv/cga_to_pal/RGB-to-Video-Converter/68.html

If it is, and I can get my hands on it then I could simply use it in conjunction with an Asus AMD Radeon HD 6450 (VGA -> Converter Board -> S-Video), So I will see if that option is available. If it turns out to be another dead end, I will go with my original plan for the meantime with the HD 4890. I will continue to pursue the CRT Mod option so any GPU with a VGA will give me the ability as it would make the CRT Future proof as well and overall better option as finding a 27" Wells Gardner would be slim to none in my neck of the woods. Though if for any reason I can't get the CRT mod done, I'm not going to just let the Cabinet sit around with nothing in it for another 10 years, I need some sort of usability out of it, and even if it isn't the best looking, I never complained or saw anything that bugged me previously when it was set up that way.

[abstract3000]

Ok so change of plans... I reached out to an old Friend who I haven't spoke to in years, who used to be a coin op back in the 80's and owned an Electronics Repair shop before retiring, I asked him if he knew anything about modding CRT, he had in fact done it and was able to pull the schematics for my Model and stated he would be willing to do the work. So in the meantime I will be having the TV RGB Modded, but was curious most people are wiring into a SCART plug, (I'm in the U.S, not sure if you are aware but that type of connector simply is non existent here) there is also the female terminals we are used to seeing, what would be the better option for overall compatibility going into the future? I guess his thoughts after speaking more to him was to add a CGA D9 plug apparently this is what Most arcade Monitors have

[Zebidee]

There can't be much difference between schematics for the 25" and 27" models, and definitely the same jungle. Even when you have the schematic there, you need to look over the TV chassis itself because there are often manufacturing differences.

Glad you've found a local friend to help with the RGB mod.

That converter you linked looks interesting - note that you'd need to provide a power supply ~12v. An old power brick should do the job, or a standard arcade DC power supply. You can solder/connect the supplied cable+plug to it. Seems well suited for use in an arcade cab.

SCART is the RGB standard input for CRT TVs in Europe, that's why many people use that connection. However, there is no need for you to copy. I (and many others) prefer to use a VGA D15 for RGB. That way you can use a plain old VGA cable to connect with your computer. The connector is also more secure, I've always found the SCART clunky. The VGA jacks are both cheaper and smaller, and easy to screw onto the back/side of a TV case.

I like the HD6450 cards - I have about five or six, couple of different brands but very similar. CRT_emulator installation is very straightforward. I was also able to use ATOM-15 on all of them to mod their video BIOS so that they are 15khz from boot. So, for example, you can access the computer BIOS and boot options using your TV.

[abstract3000]

Thanks again for all the Input, I am going to build a frame out of 2x4's this weekend to remove the tube from the cabinet and mount it into to protect the neck. This gives me the ability to move the monitor to his place for him to work on. I studied the Pinouts for the CGA/D9 & the VGA/D15 and I'm fine with either he decides to wire in there. As both pinouts have the R/G/B/GND/V-Sync/H-Sync connections it will be easy take the connection from point A to Point B and adapters are easy and cheap to come by if needed.

I chose the Asus AMD Radeon HD 6450 because I read somewhere that was one of the creators of CRT_Emudriver's personal video card at the time, so If any card will be compatible that will be one of them, and they are really really cheap. Thanks for the heads up on the ATOM-15 software I will look a bit further onto that. I finally feel relieved I know the path I'm taking, cause it was becoming a serious headache trying to figure out what converter that would work, just to find out it wasn't possible to get ahold of. I know at least know I will no longer be wrestling with the S-Video Adapter.

[buttersoft]

After using RGB, i couldn't go back

Post some pics when you get it up and running! Or come back and ask questions, i guess. To be honest, this isn't really the place for crt_emudriver or GroovyMAME support, the GM subforum is best for that, but there is a monitor involved so i'll call that enough crossover

[Zebidee]

I studied the Pinouts for the CGA/D9 & the VGA/D15 and I'm fine with either he decides to wire in there. As both pinouts have the R/G/B/GND/V-Sync/H-Sync connections it will be easy take the connection from point A to Point B and adapters are easy and cheap to come by if needed.

Whatever way you prefer is fine, but if you go for a female Dsub15 (VGA) port on the TV, you won't even have to worry about pinouts. Just use any common/standard/ubiquitous/cheap VGA male-male cable to connect your computer.

Note that, whatever connection you choose, the separate H+V sync must be combined into a single composite sync for the TV. Your mate doing the RGB modding should be aware of this.

The simplest way is to twist the H+V wires together and run it through a resistor in series (people commonly use values between 470R and 1K). The resistor is to bring the sync voltage from ~4-5v to ~0.3v for TVs. This "smushy" sync that isn't 100% perfect, but will work OK with about 99% of CRT TVs. Most people are pretty happy with this.

An alternative is to run CRT_emulator with composite sync. This is a better quality sync, but for many TVs you might not see any difference. Composite is only output on VGA pin 13, so no twisting H+V together, but you still need the resistor in series. You would want to leave off/disconnect VGA pin 14 (V sync) to avoid ghost signals from leaving it "floating".

You can even wire up your own simple composite sync circuit too, is pretty easy with some cheap logic chips or transistors, but this is probably more than you want to do.

[abstract3000]

I can definitely post photos, there is a lot of blunders in the Case my late teenage brain thought would be ok opposed to my now, and I can give some before and after shots of the monitor, wiring etc. Though for the meantime this is a picture of the cabinet up and running from sometime i think in ~2003?




Thanks for all the Help and More Pics & Questions to Come I'm sure

[abstract3000]

Well got a snapped photo today, RGB done as well my friend added an Auto Power on Circuit to the TV
More photos to come!

[Zebidee]

Looks great!

Simplest way to add an "auto power-on circuit" to a TV is to put a capacitor between the soft power-on switch terminals. When connecting to power, this adds a short delay (typically less than 1 second) before closing the switch. This is usually enough time for the TV control circuitry to wake up, and then being able to register that you've "pressed the switch".

Am I imagining a soft shadow in the middle, between the blocks of red and cyan?

[abstract3000]

well I got the TV back today, and it appears he simply used a board to put everything on, and he gave me the schematics for it as well.  (Ignore my previous squirrely ignorance ) I needed to spend some more time reading up on H-Sync & V-Sync vs Composite Sync....

So with it pinned to analog VGA Layout, a Vga to Vga Cord should work just perfectly I suppose.  When I get the Power Supply In, I will start loading Windows 7 and getting GroovyMame setup with CRT_Emudriver, and we will see how this goes

[abstract3000]

Well it appears my first test of connecting to the monitor is a Crash & Burn no success 

I used Win10 for Testing enabled the TESTSIGNING got the CRT_EmuDriver installed it found my Card and Installed AMD Radeon HD 7400 Series (CRT Emudriver) Drivers correctly.

Opened up VMMaker, (verified CRT Emudriver on the screen)
- Selected Arcade 15.7
- unchecked Extend desktop automatically on device restart
- Dropdown box to VGA_Analog_0
- Clicked on Enable EDID emulation

Unplugged the VGA from the monitor and moved it to the CRT and well.... Nothing :/ Swapped through all inputs which didn't do anything powered the TV on And off and still nothing.
When I moved the VGA back to the Monitor the Screen rez was all screwed up small to the side with lines through it indicating what i guess to be it was outputting the signal at 15kHz. So... Any ideas or suggestions? I have the schematics from the TV to the pins posted above on my VGA pinout, using a standard VGA to VGA D15 Cable.

After reading a bit and looking at my windows display settings i don't see any modelines for 640x480 available... not sure if that's the issue, but I will try to find the modelines to install and see if that option comes available, switch the monitor to that maybe and try again?

[buttersoft]

Sorry to maybe go over stuff you've covered before, but... Is the Arcade monitor known working? Is the setup monitor an LCD or a CRT of some kind? It's really unusual that an LCD would display a garbled image, esp at 15kHz.

[abstract3000]

I apologize for my description of "garbled". The setup monitor is a Dell LCD monitor. When I move the vga back from the CRT to the setup LCD, I see an image of VMmaker software extremely large but offset in the corner and there are tear lines or flashing horizontal lines through the screen until I click on disable edid emulation. And it returns back to normal.

Hope that clears that up, the lowest resolution my current settings support is 800x600 do you not think having the additional modelines installed could be the issue?

[buttersoft]

No need to apologise, garbled is probably fine for what you're talking about. I merely wanted to clarify what was going on.

Not having the modelines installed should not be a problem. Activating EDID emulation will read the monitor preset, and spoof an EDID based on that, so it should be pushing 480i when you do it. I believe you are selecting the right display head of the GPU as otherwise you wouldn't get anything onscreen, garbled or otherwise.

What is the CRT you are trying to connect to? If it's a PAL CRT, you should be using the PAL preset (at least to troubleshoot, which is where we are now). Do you own a multimeter? Most are capable of reading frequency. You could use one to read pin 13 of the VGA output and see if it reads 15kHz. It probably will, which would me it's probably not the PC at fault.

You have the TV working? With RGBS? Or you don't have any other RGBS sources, and you're trying the RGB-mod for the first time with this PC? something isn;'t

[Zebidee]

For whatever reason, the forum site has suddenly decided that I can't see the pics you've attached unless I deliberately download the file and open it in a separate viewer app.

What this means is, commenting on your post, on any post with pics directly attached, is really hard

[abstract3000]

No need to apologise, garbled is probably fine for what you're talking about. I merely wanted to clarify what was going on.

Not having the modelines installed should not be a problem. Activating EDID emulation will read the monitor preset, and spoof an EDID based on that, so it should be pushing 480i when you do it. I believe you are selecting the right display head of the GPU as otherwise you wouldn't get anything onscreen, garbled or otherwise.

What is the CRT you are trying to connect to? If it's a PAL CRT, you should be using the PAL preset (at least to troubleshoot, which is where we are now). Do you own a multimeter? Most are capable of reading frequency. You could use one to read pin 13 of the VGA output and see if it reads 15kHz. It probably will, which would me it's probably not the PC at fault.

You have the TV working? With RGBS? Or you don't have any other RGBS sources, and you're trying the RGB-mod for the first time with this PC? something isn;'t

Ok so The Monitor is an NTSC SHARP 27R-S100

It has never been hooked up to and worked with the PC This is a First time
I know the RGB Mod was done as seen in the photo above that is the monitor, My friend demonstrated the mod with a Sencore CM2125 Monitor Analyzer he has in his shop.
I took the measurement off the Multimeter I get 15.7 kHz on Pin 13, & 60kHz on Pin 14
I tried slightly adjusting Screen Voltage on the Flyback with no Success, but let me explain the following:

When disconnecting the the VGA very slowly I noticed something appear on the screen. I started just jolting the cable around and for the brief Second I saw the image show up on the CRT but quickly disappear. I discussed it with my friend who stated while a loose connection is always a possibility is more inclined to believe my connecting and disconnecting was disrupting the sync lock and i was seeing the image prior to the lock taking place. So he does not know anything about the CRT Emudriver but asked if there was a Way for the Software to Invert the signal for shits and giggles.

Hopefully i have answered all your questions, if not feel free to ask anything else and i will see what info I can get

For whatever reason, the forum site has suddenly decided that I can't see the pics you've attached unless I deliberately download the file and open it in a separate viewer app.

What this means is, commenting on your post, on any post with pics directly attached, is really hard

Sorry about that i was uploading the photos first on imgBB and doing the img tags around the link but they would not show after posting so I started attaching afterwards, I will provide the direct links below to the images

https://ibb.co/q0Wb56L
https://ibb.co/r6mTpwq
https://ibb.co/9w5x8Gy

And here is the img tagged ones let me know if you can see them

[abstract3000]

Well may have solved the issue, I can manage to get the picture on the screen, but not perfect. The black/white/Red/Blue/Green wires on the end appear to be the issue if I touch the resistor next to any of R/G/B the screen shows up in whichever hue I'm missing.  MY friend asked if there was a way to send the Signal via TTL and stated that the circuit was built for sending to a CGA monitor :/
So if the software cant bend to that spec, he would need to redesign the board at best removing the resistors and decoupling caps..... Though he has to get the PC and try and figure out what kind of Signal is being sent from the Video Card, I didn't seem to see any documentation on it but i will keep digging.

[PL1]

And here is the img tagged ones let me know if you can see them

To embed the image in your post, you need to use the actual image URL, not the page URL.

On the page, right-click on the image thumbnail and open in a new tab.

For example:
- The first page you linked to is https://ibb.co/q0Wb56L.
- The image that page's thumbnail links to is https://i.ibb.co/1sdH6cY/crt.jpg.
- Put that image URL in IMG tags like this . . .

Code: [Select]

[img]https://i.ibb.co/1sdH6cY/crt.jpg[/img]. . . and you get the full size image like this . . .

. . . or add width and/or height in pixels to scale the image. (readers can click on the image to blow it up to full-size.)   

Code: [Select]

[img width=350]https://i.ibb.co/1sdH6cY/crt.jpg[/img]

That said, it is better in the long term to upload images either here in your thread or -- the preferred approach -- upload them to the latest stickied "NOT A PROJECT" thread at the top of the Project Announcements sub-forum.
- IIRC Saint backs that thread up separately from the rest of the forum so the rest of the backup runs more quickly.
- Many great project threads have been rendered almost useless due to image hosting companies either going out of business, or changing their terms of service, or moving to new servers, or sites being hacked by spammers, or . . . .


Scott

[Zebidee]

Thanks for sharing that schematic.

The LM555-based timer circuit is an interesting approach. I've achieved same effect by simply using a capacitor (say, 100uF) across the TV power button terminals (you can also add a resistor in series to increase the delay). However, the timer circuit is elegant and may work in situations where the cap trick won't.

Concerning the RGB input lines... I guess those 1.3k resistors are part of the OSD-MUX RGB mod. I'd normally expect to see those 100nF caps AFTER the resistors, and physically as close as possible to the jungle/OSD IC. I don't know why they are on that input breadboard and before the resistors. However, for all I know, there may be extra caps inside the TV as well, closer to the IC. 

That circuit to combine the sync... basically just an NPN transistor, which will give you AND logic sync. This is probably OK for games at 240p and other non-interlaced video modes, but not so great for interlaced modes (like those you typically use for the PC's desktop). This is because it'll lose all the horizontal timing pulses that are normally expected during the vertical sync interval. Some TVs can't actually lock on properly without them, at least for interlaced modes. It also won't work with anything but negative sync on both H&V.

Even if you just twist the wires together you'll still get those horz timing pulses during the vertical sync period, but their polarity will be reversed

So, there are other options to try for the sync, including some that are quite simple (e.g. generating composite sync output via VMmaker).

If you want to know more about sync variants, I suggest you have a look at this blog post from Ste of Retrovision.

Also, VGA sync voltage will be too high for TVs, and there is nothing on the sync lines to pull the voltage down except those 100ohm resistors, which are not sufficient.  You could put another resistor in series *after* the transistor, say ~470R/510R/680R to pull the sync voltage down from ~4-5v to something like the ~0.3v expected by TVs.

Lastly, the blanking signal appears to be raw 5v inserted directly. No diode or current limiting resistor or anything? The TV only has to detect the voltage. Another thought: often there are multiple blanking voltages for different modes. TV might actually be happier with something like 3v. Modders will often put in a basic voltage divider, involving a potentiometer, to "tune in" the blanking signals. Once the needed blanking voltages are known, the pot can be replaced with permanent resistors.

For convenience, I've linked the schematic below.

[abstract3000]

@zebidee thank you sir! I greatly appreciate the time you took to provide that feedback. My friend set this up apparently to act as a cha monitor like the original arcade ones without truly understanding the context I suppose in which the monitor was being used.

If I used crt_emudrivers csync option would that just entail disconnecting the h&v sync and leaving the pins 13 &14 with nothing attached?

If you have some ideas on how to approach the synch issue I could scan the actual schematics for the television and upload them for you to view?

Again thank you so much for taking the time

[buttersoft]

Composite sync from crt_emudriver would be delivered on VGA pin 13. I think, based on the above, you'd just bypass the H- and V-sync combiner circuit and feed the c-sync directly to the TV

[Zebidee]

Composite sync from crt_emudriver would be delivered on VGA pin 13. I think, based on the above, you'd just bypass the H- and V-sync combiner circuit and feed the c-sync directly to the TV

Yes, do exactly this, except feed the composite sync from pin 13 through a resistor (1 suggest 1K, but really anything from 470R to 1K should be fine). Then disconnect pin 14 altogether, otherwise you might get ghost signals. This is the simplest neat solution.

If you want to get fancy, or your friend does, you could try this XNOR composite sync circuit by Tomi Engdahl.. It only needs one quad-logic chip (four XOR logic gates on a single chip), a couple of caps and a couple of resistors. There are a few circuits on that page, so I've linked to a pic of the one I mean below.





Ste (Retrovision) also suggests a good/simple XNOR sync circuit in his blog article (linked above) using 3 different logic chips. This definitely works well, though I'd suggest some decoupling ceramic capacitors (100nf on H, 1uF on V) in series on the H+V sync inputs, and similar value bypass cap(s) for the +5v Vcc inputs (bypass caps, between Vcc and GND, help stabilise the voltage supply).

As suggested above, add a ~1K resistor in series to the sync outputs of whatever option/circuit you use, to pull the voltage levels down to ~0.3v for TV.

If you want to be really clever and make the sync even tighter, add a schottky diode (IN5817, IN5818, IN5819 all good) after the resistor, between the sync output line and GND, in reverse-bias orientation (anode to GND, cathode [end with stripe] to sync). The diode will "clamp" the sync to GND, effectively giving it a reference and making it more stable. Some won't bother, but the diodes are cheap and I find it can help in some cases. I suggest schottky diodes as they are good for fast signals and, being germanium based, have a convenient voltage drop of ~0.3v.

Can draw my suggestions onto a circuit diagram if you are seriously interested.

[abstract3000]

@Zebidee or @buttersoft

I find myself in between a rock and a hard place, as I sit as the middleman passing information between them with my knowledge painfully lacking.  I have a friend who knows electronics and can do what's asked, but may not necessarily understand the context of what's being asked or what's trying to be achieved. Whereas here on the forums We have experts that know the context and what is trying to be achieved.

Today i got some disappointing news in which my friend believes is limitations of the software not outputting a Digital signal but rather analog signal. Here are the points he made:

• Software only appears to produce analog RGB output, Suspected that a Card capable of Digital RGB would make the CGA option show up and switch the signal from analog to digital.
• The Jungle IC Input appears to be locked at Digital (Has no way of knowing if it will take analog) Though if it did it would require a software change that is not in the service menu custom reprogramming of the EEPROM
• Circuit interface works fine with a true CGA (TTL) Signal, though does not believe analog signal was ever considered as there is no decoupling capacitor or shunt resistor in the RGB feed from the CPU to Jungle, Just a Single Voltage dropping Resistor inline.
• Believes the only way to do it would be to send a true CGA signal or interface directly to the neck board (Which he does not recommend)

I'm not sure in particular why he keeps bringing up CGA? I have photos of messing with the board and briefly getting the signal to show up so I know the Software does have the capability of moving the Image to the TV but his response to that was as Follows:

When i was touching the board I was passing the 5V (From turn on circuit) to the signal pins effectively pulling up the signal to close to the TTL Levels CGA used.

He stated he could add resistors to do that in the circuit but he sees 2 potential issues:
- I could potentially lose a lot of Contrast
- He also is worried about running injected voltage back through the video card may cause damage.
(He could decouple with capacitors, but stated that might but us back where we started)

The last bit of advise was not to confuse the signal itself with the resolution. CGA is a TTL level signal meaning the 3 colors only have two modes (on and off) The CGA color pallet can only produce 16 colors which is fine for a TV's OSD. The interface injects the signal from the computer into the jungle at the same spot the CPU injects the OSD.

So at this point I'm not sure what to do, would it be helpful to scan the TV's Schematics I have?
Does CRT Emudriver have the ability to push out a digital Signal opposed to an Analog Signal?
Is he right in his assumption that injecting the 5V would cause issues with the contrast and potentially ruin the Video Card?

I really appreciate any time or assistance

[Zebidee]

@Zebidee or @buttersoft

I find myself in between a rock and a hard place, as I sit as the middleman passing information between them with my knowledge painfully lacking.  I have a friend who knows electronics and can do what's asked, but may not necessarily understand the context of what's being asked or what's trying to be achieved. Whereas here on the forums We have experts that know the context and what is trying to be achieved.

Today i got some disappointing news in which my friend believes is limitations of the software not outputting a Digital signal but rather analog signal. Here are the points he made:

• Software only appears to produce analog RGB output, Suspected that a Card capable of Digital RGB would make the CGA option show up and switch the signal from analog to digital.
• The Jungle IC Input appears to be locked at Digital (Has no way of knowing if it will take analog) Though if it did it would require a software change that is not in the service menu custom reprogramming of the EEPROM
• Circuit interface works fine with a true CGA (TTL) Signal, though does not believe analog signal was ever considered as there is no decoupling capacitor or shunt resistor in the RGB feed from the CPU to Jungle, Just a Single Voltage dropping Resistor inline.
• Believes the only way to do it would be to send a true CGA signal or interface directly to the neck board (Which he does not recommend)

I'm not sure in particular why he keeps bringing up CGA?

Your friend is confused. CGA is an old computer graphics/display output standard that allows 4-bit color (16 colours). For convenience, it is designed to be compatible with domestic CRT TVs @ 15.7khz. This is why old games/software have limited colours and chunky resolutions.

Some people think that CGA = 15.7khz display, but this is simply not true.

Colour CRT TVs themselves are analogue and not limited by CGA, and can display essentially infinite colours, within practical limitations. This is why we could enjoy movies on them, with all kinds of shades and colours, back in the day. We can display higher resolutions than CGA on a CRT TV. CGA defines what some (old) computers can output, not what the CRT TVs can do.

So, the whole CGA and "digital RGB" discussion misses the point and is just distracting. The CRT TV definitely 100% takes an analog RGB signal.

The computer's video card takes the digital video information it creates, and converts that into analogue space using a dedicated onboard DAC (Digital Analog Converter) chip. Computer have done this since the dinosaurs. It is only more modern video cards and GPUs that have dispensed with DACs and output digital-only formats (like HDMI). This is why, for CRT_emulator and similar software, we need to use older video cards with analogue outputs like VGA. That is the whole point.

The sync itself is a TTL-level logic signal, though it might be thought of as both digital and analogue. On an oscilloscope it appears a squared wave, essentially either on or off.

I have photos of messing with the board and briefly getting the signal to show up so I know the Software does have the capability of moving the Image to the TV but his response to that was as Follows:

When i was touching the board I was passing the 5V (From turn on circuit) to the signal pins effectively pulling up the signal to close to the TTL Levels CGA used.

He stated he could add resistors to do that in the circuit but he sees 2 potential issues:
- I could potentially lose a lot of Contrast
- He also is worried about running injected voltage back through the video card may cause damage.
(He could decouple with capacitors, but stated that might but us back where we started)

Move the in series capacitors on the RGB signal inputs. They should be on the other side of those resistors, and as close to the IC as practically possible (distance matters).

The RGB signal inputs Need 75R termination (resistor to ground) for the RGB signals.

The sync input needs a resistor in series, as the video card output is too high (around 3.5-5.0vpp), and the TV industry standard expects 0.286vpp. If you assume VGA sync peaks at 5v (probably a bit lower), and there is 75R termination at the TV end, then a 1K resistor gives you exactly 0.349v (close enough).

Note that sync has *nothing* whatsoever to do with contrast or image brightness. It carries no picture information. It simply tells the TV when to draw new lines and when to start the next screen refresh.

I don't understand why he's worried about "running injected voltage back through the video card". There is no voltage "injected" to the card anywhere, even with the alternative sync circuits suggested. The TV and video card would only share a video ground connection, which is standard/normal.

You would probably want to de-couple the H&V sync inputs, to the custom composite sync circuit, with small ceramic capacitors that are not on the schematics I linked (I'd suggest 0.1uF/104 or 1uF/105 values). This de-coupling is more about making sure the composite sync circuit works properly than about protecting the video card from "injected voltage".

Try putting a pot on the 5v blanking signal so you can "tune it in", then replace the pot with a normal resistor. 5v may work for some TVs and not others. True blanking voltage required may be more like 2-3v, every model TV can be different. Schematic might help you to narrow it down.

The last bit of advise was not to confuse the signal itself with the resolution. CGA is a TTL level signal meaning the 3 colors only have two modes (on and off) The CGA color pallet can only produce 16 colors which is fine for a TV's OSD.

This is irrelevant, The TV is not limited to CGA pallet.

The interface injects the signal from the computer into the jungle at the same spot the CPU injects the OSD.[/i]

This is fundamentally correct. It is an OSD-injection RGB mod.

So at this point I'm not sure what to do, would it be helpful to scan the TV's Schematics I have?

Probably not necessary, though I guess it won't hurt anything. Referring to the schematic could help us determine the correct values for in-series resistors on the RGB signal inputs and correct blanking voltage.

Does CRT Emudriver have the ability to push out a digital Signal opposed to an Analog Signal?

This is irrelevant, forget about it.

Is he right in his assumption that injecting the 5V would cause issues with the contrast and potentially ruin the Video Card?

I honesty do not fully understand what he wants to do here. There is no need to "pull up" the RGB or sync. Don't do it.

I really appreciate any time or assistance

No worries.

I have more to say, but am going to finish this post as it is long enough already. Next, I'd like to move on and introduce you to the OSD RGB mux method developed by Mark Ozlad and Syntax (with help from others) from the Shmups forum.

[abstract3000]

Thank you so much for you Response. I will try to make more sense of this in the meantime He sent me  link to how he re did the board and has been looking here https://crtdatabase.com/modding/rgb-via-mux, and it appears we are looking for the CGA Preset is the TV....

I really appreciate the quick response

[Zebidee]

How about you upload that schematic you have? I can see if it is the same as what I've got.

EDIT: or you could just tell me if it is the same as this one
https://www.manualslib.com/download/780770/Sharp-27r-S50.html

[abstract3000]

Sorry there is a Fold in Page A/B, If the fold lands on info you need I can get the info for you

[Zebidee]

Thank you so much for you Response. I will try to make more sense of this in the meantime He sent me  link to how he re did the board and has been looking here https://crtdatabase.com/modding/rgb-via-mux, and it appears we are looking for the CGA Preset is the TV....

I really appreciate the quick response

OK, yes that is basically the same approach I suggest. That site you linked doesn't seem to acknowledge that different TVs are... different.

I've attached that popular RGB OSD MUX diagram. However, you will need to change some resistor values.

You can work this out by looking up the schematic and plugging some values into this OSD mux RGB calculator spreadsheet. The spreadsheet linked is read only, you need to copy it then plug in values on your own copy.

The schematic I have says that your OSD RGB inline resistors are 6.8k, so over-write 5600 with 6800.
EDIT: the schematic you just uploaded seems to have the same values, 6.8K

There are no diodes on the OSD RGB inputs, so we'll over-write 0.7 with 0.0

We WILL add 75R termination resistors, as marked in the diagram, so we can leave the 75 there.

We want the output voltage to be 0.7 or over. If leave the default at 1k (1000) for the Ext RGB inline resistor, we get 0.68v. Close. If we bump it up to the next standard value of 1.2k (1200) then it will be 0.78, a little high. So, choose 1K or 1.2K for the ext RGB inline resistors.

The OSD blanking signal has a 6.8K resistor on it. The spreadsheet suggests we use 3.75K to the 5v blanking, to achieve 1.8v. It also suggests just using the same value resistor, 6.8K. Confusing much? Try a 10K pot (with only two terminals attached), find what value works, then replace with a fixed resistor. Don't just assume that 5v blanking will work.

You'll probably want to put a switch on that blanking voltage, so you can retain input/OSD options. I'm not sure where you'll be getting your 5v, there are a few options. Try starting from the Vcc/power pins, on those main jungle and OSD ICs, and working back towards the voltage regulator(s).

EDIT thanks for the schematic. Different to what I linked, but basic info seems the same.

I see that someone has pencilled in some diodes on the OSD RGB lines. If they are there, then the Ext RGB inline resistors will need to be 1.3K, just like your friend has already done. But I don't see the 75R termination resistors.