VGA => composite to a CRT TV without scaling?

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spidersfrommars
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Re: VGA => composite to a CRT TV without scaling?

Postby spidersfrommars » Thu May 02, 2019 2:52 pm

With the scaler off, each core will run at native resolution. The only way to force 480i would be to use a custom video mode through the scaler.
Another note is that you need to tell the scaler in the custom videomode to use 15khz. I havent tried 480i but my setting from this threadhttp://www.atari-forum.com/viewtopic.php?t=34480

in mister.ini
you put:
vga_scaler=1 ; set to 1 to connect VGA to scaler output.
video_mode=video_mode=320,16,30,34,240,2,3,22,6400 ;240p

;for per core settings you do something like this:
[gameboy]
vga_scaler=1





i know this isnt 480i so you will have to play around with it. On a side note this is great for making core that dont natively support 15khz work with the adapter. Please post your 480i video mode if you get it, id like to add it to my list of usable videomodes with my adapter. Hope i helped!

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Thu May 02, 2019 3:27 pm

Thank you for the insightful info! Once I get the adapter from Aliexpress and have it all connected, I will definitely report back. I'm sure I'll need more help, lol.

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Re: VGA => composite to a CRT TV without scaling?

Postby Sorgelig » Thu May 02, 2019 9:51 pm

Interlaced modes are the same as progressive half height modes.
So, 480i is the same as 240p.
Old computers/consoles in most cases output progressive modes. TVs don't really care if it's interlaced or progressive as long as it provides correct lines per field.

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Tue May 07, 2019 5:23 pm

DrOG wrote:
digitron wrote:
DrOG wrote:Sorry, my bad :oops: I was in a hurry and forgot to logout...
So here's the link:
https://www.aliexpress.com/item/Arcade- ... 4c4dP7CSBR
And as compensation two screenshots...

I purchased that converter, thanks for the recommendation. Do you have any info on how you wired it to the Mister or IO board? Thanks! :)

I wired it to MiST, but pinout is the same...
VGA pin - Function
#1 - RED
#2 - GREEN
#3 - BLUE
#13 - HSYNC/CSYNC
#14 - VSYNC
#5, 6, 7, 8, 10 - Ground


How do you power the converter? I see it comes with power cable but no AC 12v adapter?

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Wed May 08, 2019 4:09 am

I have an external MOLEX psu (see attachment), noname, but works perfectly. I use a homemade converter wire (the power cable shipped with the card soldered to a MOLEX male connector's GND and 12V lines). I have a GBS-8200 as well, that's fed by the another GND and the 5V lines...
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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Wed May 08, 2019 3:53 pm

DrOG wrote:I have an external MOLEX psu (see attachment), noname, but works perfectly. I use a homemade converter wire (the power cable shipped with the card soldered to a MOLEX male connector's GND and 12V lines). I have a GBS-8200 as well, that's fed by the another GND and the 5V lines...


Thanks!

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Thu May 09, 2019 4:23 am

DrOG wrote:
digitron wrote:
DrOG wrote:Sorry, my bad :oops: I was in a hurry and forgot to logout...
So here's the link:
https://www.aliexpress.com/item/Arcade- ... 4c4dP7CSBR
And as compensation two screenshots...

I purchased that converter, thanks for the recommendation. Do you have any info on how you wired it to the Mister or IO board? Thanks! :)

I wired it to MiST, but pinout is the same...
VGA pin - Function
#1 - RED
#2 - GREEN
#3 - BLUE
#13 - HSYNC/CSYNC
#14 - VSYNC
#5, 6, 7, 8, 10 - Ground


Hey DrOG, I'm splicing the RGB connector from the converter (smaller connector?) into a VGA cable. I'm going to connect it this way to the VGA port on the IO board once I have it completed. Does this sound ok? Which pin on the VGA cable do I use for ground?

I found this diagram, looks like ground is the shielded wire around the main cable:

Image

R,G,B, are good so far. Looks like H SYNC & V SYNC are on VGA pins 13 & 14.

Image
Image

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Thu May 09, 2019 2:55 pm

digitron wrote:...
Hey DrOG, I'm splicing the RGB connector from the converter (smaller connector?) into a VGA cable. I'm going to connect it this way to the VGA port on the IO board once I have it completed. Does this sound ok? Which pin on the VGA cable do I use for ground?...

It seems to be OK.
The best is to use a multimeter to determine which wire connects to which pin. Shielding is not always connected to ground, although it should be... It's recommended to use pin(s) #5 and/or #10 as GND, if possible (RGB GNDs - pins #6-8 are not always connected as well...).

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Thu May 09, 2019 3:07 pm

DrOG wrote:
digitron wrote:...
Hey DrOG, I'm splicing the RGB connector from the converter (smaller connector?) into a VGA cable. I'm going to connect it this way to the VGA port on the IO board once I have it completed. Does this sound ok? Which pin on the VGA cable do I use for ground?...

It seems to be OK.
The best is to use a multimeter to determine which wire connects to which pin. Shielding is not always connected to ground, although it should be... It's recommended to use pin(s) #5 and/or #10 as GND, if possible (RGB GNDs - pins #6-8 are not always connected as well...).


Thanks! :cheers:

Looks like the IO board should have the outside of the socket grounded, so I think it should be fine.

Image

Am I supposed to solder these two clips from the d-sub connector to the IO board?

Image

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Re: VGA => composite to a CRT TV without scaling?

Postby Sorgelig » Thu May 09, 2019 7:40 pm

digitron wrote:Am I supposed to solder these two clips from the d-sub connector to the IO board?

yes

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Fri May 10, 2019 4:22 am

digitron wrote:...
Looks like the IO board should have the outside of the socket grounded, so I think it should be fine.
...

The problem is not the IO board, but cheap cables! I saw some examples the shielding was not soldered to the outside of the socket, and the same was true in aspect of RGB GNDs (pins #6-8) ... As I see on the IO board's diagram, all the necessary pins are soldered to GND, so it's fine to use #5 and/or #10 as I recommended earlier...

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Re: VGA => composite to a CRT TV without scaling?

Postby spidersfrommars » Fri May 10, 2019 4:28 am

Yeah for sure its the vga cable, cheap vga cables dont have all the wires connected, i had the same issue. I ended up buying a vga breakout board like this https://www.ebay.com/i/153414037555?chn=ps I wired all the pins and it works good.

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Fri May 10, 2019 3:24 pm

DrOG wrote:The problem is not the IO board, but cheap cables! I saw some examples the shielding was not soldered to the outside of the socket, and the same was true in aspect of RGB GNDs (pins #6-8) ... As I see on the IO board's diagram, all the necessary pins are soldered to GND, so it's fine to use #5 and/or #10 as I recommended earlier...


Unfortunately my cheap VGA cable doesn't have wires on pins #5 or #10, I checked them with a meter. :/ I appreciate all your help DrOG, I got the ground connected to the outside ground wiring on the vga socket. I'm waiting on a couple parts then once I get this IO board connected I'll finally be able to test this connected to my JVC PVM. :)

spidersfrommars wrote:Yeah for sure its the vga cable, cheap vga cables dont have all the wires connected, i had the same issue. I ended up buying a vga breakout board like this https://www.ebay.com/i/153414037555?chn=ps I wired all the pins and it works good.


Good to know! Thanks!

Sorgelig wrote:
digitron wrote:Am I supposed to solder these two clips from the d-sub connector to the IO board?

yes


Thanks Sorg!

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Fri May 10, 2019 7:55 pm

DrOG wrote:I have an external MOLEX psu (see attachment), noname, but works perfectly. I use a homemade converter wire (the power cable shipped with the card soldered to a MOLEX male connector's GND and 12V lines). I have a GBS-8200 as well, that's fed by the another GND and the 5V lines...


Aliexpress took me for a spin on that converter, under the Item Specifics it says "Power:DC+12V 2A +/- 0.5v", under the Product Description, it says "*POWER INPUT: DC+8-5V *CONSUMPTION:1.5W MAX". Thanks again for the info, its 12V right?

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Sat May 11, 2019 6:33 am

If you mean the GBS-8200, mine accepts everything between 5 to 18 Volts, but I don't recommend this converter... It's firmware is a piece of cr@p, has poor compatibility in aspect of non-standard input signals, and adds lag (it has a frame buffer).

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Sun May 12, 2019 4:14 pm

@DrOG, what are you using for a protective case for this aliexpress s-video adapter pcb? Did you 3d print something? If so, mind sharing it? :)

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Sun May 12, 2019 5:10 pm

I use a small lunchbox bought in a local clothing store (KIK). Gonna upload pictures if you are interested (it was very cheap and the board fits (near) perfectly).
Last edited by DrOG on Sun May 12, 2019 5:24 pm, edited 1 time in total.

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Sun May 12, 2019 5:16 pm

Sure, pics please :D

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Sun May 12, 2019 7:07 pm

digitron wrote:Sure, pics please :D

Here you are (it was 0.59€/piece), I bought 2 of them, and used the purple one - the white is a spare unit...
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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Sun May 12, 2019 7:12 pm

Nice!

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Re: VGA => composite to a CRT TV without scaling?

Postby cbo2188 » Sat May 18, 2019 10:02 pm

Does anyone have any experience with this one

https://www.antoniovillena.es/store/pro ... o-adapter/

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Re: VGA => composite to a CRT TV without scaling?

Postby Hewhoisred » Sun May 19, 2019 9:04 am

No direct experience, but apparently it works fine, as long as you use his special version of the IO board, available only from his shop. If you don't you'll have no audio. Read the product description carefully, and you'll see he says this.

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Re: VGA => composite to a CRT TV without scaling?

Postby digitron » Sun May 19, 2019 3:08 pm

DrOG wrote:
digitron wrote:...
Hey DrOG, I'm splicing the RGB connector from the converter (smaller connector?) into a VGA cable. I'm going to connect it this way to the VGA port on the IO board once I have it completed. Does this sound ok? Which pin on the VGA cable do I use for ground?...

It seems to be OK.
The best is to use a multimeter to determine which wire connects to which pin. Shielding is not always connected to ground, although it should be... It's recommended to use pin(s) #5 and/or #10 as GND, if possible (RGB GNDs - pins #6-8 are not always connected as well...).


Hey DrOG, just wanted to say thank you very much, the converter works great! :) My case is a super fancy Postal cardboard box (for now), lol.

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Re: VGA => composite to a CRT TV without scaling?

Postby DrOG » Sun May 19, 2019 7:16 pm

@digitron: You're welcome!

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Re: VGA => composite to a CRT TV without scaling?

Postby Sorgelig » Sun May 19, 2019 9:24 pm

In theory, it should be possible to encode CVBS inside the FPGA.
Just need someone self-motivated to implement it.
Currently you can use CVBS from MiSTer directly - but just monochrome. You need to switch the SOG switch to "on" and enable YPbPr output in MiSTer.ini


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