Help with Extron RGB

[Soxyboy26]

I recently got myself an Extron Rxi202, alongside a Sync Strike, to use with my xbox and crt tv, In order to try to get some scanlines.

I made a cable to connect from the sync strike terminals to the db9 Input on the extron, all seems ok (I get the scanning frequencies correct on the display), but I'm struggling with the bnc outputs to the rgb scart input on the tv.

I'm using this adaptor via the RGBS outputs of the extron

http://www.ebay.co.uk/itm/Hama-Scart-to ... 0827344423

But I guess it's not that simple, I just get a scrambled screen. I'm guessing that the tv needs to be forced into rgb mode or something via a pin that's not connected.

are there any ready made cables from RGBS BNC to scart?

[Fudoh]

are there any ready made cables from RGBS BNC to scart?

they would be the same. If your TV requires a switching voltage, you have to add a 3V power supply to Pin 16 of the scart connector. Two AA batteries for example.

[Soxyboy26]

Right, I see, thanks.

It was speculation on my part, would there be any other likely issues with my setup, do you know?

Also, for a battery, would it by positive to pin 16? Where does negative terminal connect?

Thanks in advance!

[Fudoh]

If you have any other console system, you can confirm this problem by just removing the blanking voltage from Pin 16. Probably easier this way around.

Battery: yes + to Pin 16, - to any ground.

I always have a hard time understanding why people choose RGB interfaces with those old DSub9 inputs, when the majority of interfaces available have proper HD15 inputs.

On some interfaces I experienced problems with the dedicated "S" single sync output. Using the H-Sync output or just combining H+V Sync by hand sometimes seems easier.

[Soxyboy26]

Call it bad research on my part... I found out the hard way, and had to hack up a cable and read about extron's non standard wiring... I'd certainly recommend one with a 15 pin input for ease of use.

I'll see if I can get some power to pin16 then, hopefully that is my only issue.

Sounds a good way of testing with another console too.

Thanks Fudoh

[Overkill]

I have 1 unit of that Extron RGB model, fortunately with came with two db9 to VGA cable. Im using an 4 bnc to scart from keene and is working great. Before buying the cable from keene i tryed that Hama adapter you have and no good, just a rolling image.

I grab a bargain at the time, but the prices at the keene oficial site are high. You can just get an normal 5 bnc to vga, and an "UMSA - Ultimate SCART Adapter" from Arcade Forge. It will be almost the same price, but you can use it in future for other things

http://arcadeforge.net/UMSA:::15.html?l ... 610f23133d
http://www.keene.co.uk/electronics/prod ... mycat=4593

[Fudoh]

but that's bad reasoning. Just because the Kenne cables are expensive, doesn't mean that they do anything differently - from a technical standpoint.

@Soxyboy26: of course you tried both the switch positions on the Hama adapter, didn't you ?

[Soxyboy26]

Yes! I've had it open too just to ensure that the right pins are connected, it looks ok. I tried a Dreamcast rgb cable and removed pin 16 - whilst it didn't work correctly, it gave a different result. The dreamcast was just dark, whereas the extron xbox setup is showing a bit of unstable garbage. At least I know the tv requires the rgb blanking signal now, although I suspect that somehow there is another issue after the extron. Maybe the c sync issue you mentioned Fudoh, or maybe the cabling issue Overkill mentioned? I still need to attempt power to pin 16 , just wondering how I'm going to do it with my poor soldering skills!

[Soxyboy26]

Well, I sort of managed it. I wired a battery and got an image on screen with some distortion at the top of the screen.

Flipping DDSP on however gave a stable image pretty similar to as if the extron wasn't there at all - no scanlines. I guess the tv doesn't want to play ball with it. I'm fairly surprised (and disappointed!) as the tv is pretty basic, no real processing options at all. I wanted to use it as it gives a decent picture - PS1 looks great through it.

Any suggestions, or is a new CRT the only option here?

[Overkill]

Using an extron RGB to get the pseudo 240p look is a "hit or miss". You can try the same setup in 50 more CRT tv's and get the same result. I tryed it on five crt tvs or more, and only on my sony PVM worked. I don't remember well, but i think you need to have DDSP off to use that feature.

[Soxyboy26]

Hmm, may have wasted my time there then! I can't see me getting a PVM or similar anytime soon. Wonder if a Trinitron would work, there's a chance I could get hold of one the, perhaps.

[Fudoh]

what kind of games do you want to convert anyway ? A direct 480i to 240p only works well on a very limited number of games.

[Soxyboy26]

All 2d sprite stuff, shmups, fighters, 16 bit platformers, that kind of thing. PC Engine, Megadrive, SNES and arcade was what I've been aiming towards.

[Fudoh]

Doesn't make sense. All those systems output in 240p already. What purpose would the Extron have ?

[Overkill]

I think he is talking about emulating all that plataforms on a xbox 1.

[Fudoh]

ah, ok - probably. I think we can all agree that for a proper setup, real down conversion is the way to go. As in Emotia, UVC or Genius.

[Overkill]

Or MIMO Genius Box II:D

[Soxyboy26]

Yes, emulating on the xbox, I could have been clearer.

I was looking for a cheap solution, sometimes there isn't a cheap solution perhaps. Thank you both for your help though.

A slightly different question then, but with the same objective:

The native resolution of a PC Engine or a SNES suggests that they don't output square pixels. With that in mind, is it even worth attempting a pixel perfect emulation of these systems on something like an xbox?

[Overkill]

Allmost every xbox emulator have the pixel perfect mode option, at least the majority of the "madmab" ones, but i can't remember if the Pc engine and snes have that option on it.

The cheap option for you to get correct emulation for those systems is to grab an used WII console, softmod it, and then instal these emulators: "WiiMednafen" for most consoles including pc engine, "Snes 9x Gx". These two emulators output in original resolution with an scart RGB cable, and even with the component cable. Turn off all the filters and you will end with a very good emulation, much better than the Xbox 1.

[Soxyboy26]

Yeah, I've heard Wii emulation is good.

It seems to me though that pixel perfect mode is a bit misleading when it comes to certain machines. Similar to Capcom CPS, sometimes,pixels aren't perfectly square. With pixel perfect mode on xbox SNES emulators, the screen isn't filled and the viewable aspect ratio isn't 4:3, whereas a real SNES would fill a 4:3 screen. So it seems to me that on an xbox there will always be a compromise - either no distorted pixels but an incorrect overall aspect ratio, or a correct ratio but distorted pixels that will likely have to masked by a filter. I reckon an xbox can only output square pixels or sometimes an anormorphic widescreen pixel ratio?

I think this is why people often get confused with CPS games, they think that they are in a near widescreen aspect because they are 384 x 224, whereas really a true machine would squash that resolution to fit a 4:3 screen.

Ultimately, bearing in mind to achieve scanlines on an xbox you need to use perfect pixel placement (but end up with wrong aspect), I'm not sure it's worth the effort and expense to get all the extra kit required. Just wondering if anyone agrees with me on this or whether I've got it wrong?

[Fudoh]

You need proper 1:2 scaling on the vertical (linedoubling), but I wouldn't worry about the horizontal. You can allow the emu to scale the native resolution to the XBox's full pixel width. You must not think about pixel perfect horizontal resolution when dealing with analogue signals.

[Soxyboy26]

Can I ask why you say that? It seems to my eyes that those settings introduce distortion, especially with horizontal scrolling that will judder between unevenly sized pixels.
is it that you feel this is more accurate than an incorrect aspect ratio?

[Fudoh]

with horizontal scrolling that will judder between unevenly sized pixels.

I have no idea about the XBox's emu/scaling capabilities. If that's happening, then the scaling algorithm is crappy....

[Soxyboy26]

Well it's hardware or software filters can hide this well.

But the xbox can generally output 640x480. If you double the SNES native hori resolution of 256 to 512, then there's still a pretty big gap to the xbox's 640. Without filtering the scaling then there will always be distortion wont there, regardless of platform? (Unless the actual emulators resolution output can be changed to match the emulated game?

[Fudoh]

The XBox's horizontal resolution is 720, not 640.

It depends on your definition of filtering. If the scaling algorithm is good enough, you don't need filtering. Just doubling the native horizontal resolution and padding the rest with black doesn't cut it, that's of course right.

[Soxyboy26]

I thought 720 was a widescreen output on xbox, whoops.

Is my theory about non square pixels incorrect then? That its actually all about scaling?

[Fudoh]

Nearly all SD and ED sources have non-square pixels. 720x480i/p is standard 4:3 SD/ED, despite the 3:2 pixel ratio.

[Soxyboy26]

Well that blows my mind and everything I thought I knew!

Anyway, I think im stuck with 480i and filters then, as far as the xbox goes anyway...

[Fudoh]

*IF* you can get your XBox to show emus with a linedoubled vertical resolution (e.g. 448 active lines with the rest padded black) and nearly full horizontal resolution, don't worry about a little filtering. You should look into a VGA > Emotia > CRT setup setup. The down conversion to real 240p helps a lot and easily counters the effects the filtering might have.

[Soxyboy26]

Well I have a VGA transcoder, so that's not out of the question. Emotias seem hard to come by on UK EBay, but I'll keep my eyes open...!