Main > Monitor/Video Forum
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Hey there, i've edited the info on converters in that guide as it was a bit out of date, sorry.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 :)