Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Cables

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Lawfer
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Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Cables

Post by Lawfer »

Scart: https://retro-access.com/products/dream ... cart-cable

BNC: https://retro-access.com/products/dream ... -bnc-cable

Does anyone know if these fixes out-of-the-box the overblown video and RGB levels?
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Fudoh
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Fudoh »

And for those in Europe Retrogamingcables UK opened preorders for his version of the Scart cable today as well.

https://www.retrogamingcables.co.uk/seg ... -480P-MODE
Last edited by Fudoh on Thu May 02, 2019 6:52 pm, edited 1 time in total.
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Lawfer
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Lawfer »

Fudoh wrote:And for those in Europe Retrogamingcables UK opened preorders for his version of the Scart cable today well.

https://www.retrogamingcables.co.uk/seg ... -480P-MODE
Thanks for pointing it out, did RGC confirm whether or not it attenuates video levels and rgb levels?
thebigcheese
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by thebigcheese »

Citrus was involved with the Retro Access one, anyway, so while I can't confirm or deny how the levels look, he seems like he knows what he's doing.
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Lawfer
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Lawfer »

thebigcheese wrote:Citrus was involved with the Retro Access one, anyway, so while I can't confirm or deny how the levels look, he seems like he knows what he's doing.
Great news, Drew just confirmed to me that their Dreamcast cables are indeed attenuated!
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citrus3000psi
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by citrus3000psi »

Yes, RGB max levels are right at 700mv.

The CSYNC also has the serration pulses so it works on the BVM D & A series monitors that lack the vcr button in 480p mode.
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Kez
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Kez »

citrus3000psi wrote:The CSYNC also has the serration pulses so it works on the BVM D & A series monitors that lack the vcr button in 480p mode.
Wow, that's awesome! So anyone who has an annoying curve at the top of your picture when using DC in 480p - this will eliminate it.
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Gunstar
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Gunstar »

Lawfer wrote:
Fudoh wrote:And for those in Europe Retrogamingcables UK opened preorders for his version of the Scart cable today well.

https://www.retrogamingcables.co.uk/seg ... -480P-MODE
Thanks for pointing it out, did RGC confirm whether or not it attenuates video levels and rgb levels?
I asked RGC about high RGB levels and detail clipping and got a short reply saying:
we have resistors and caps on the RGBS lines
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maxtherabbit
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by maxtherabbit »

citrus3000psi wrote:Yes, RGB max levels are right at 700mv.

The CSYNC also has the serration pulses so it works on the BVM D & A series monitors that lack the vcr button in 480p mode.
Gunstar wrote:
Lawfer wrote:
Fudoh wrote:And for those in Europe Retrogamingcables UK opened preorders for his version of the Scart cable today well.

https://www.retrogamingcables.co.uk/seg ... -480P-MODE
Thanks for pointing it out, did RGC confirm whether or not it attenuates video levels and rgb levels?
I asked RGC about high RGB levels and detail clipping and got a short reply saying:
we have resistors and caps on the RGBS lines
are there full attenuator networks to keep impedance matched? or just series resistors?
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Gunstar
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Gunstar »

maxtherabbit wrote: are there full attenuator networks to keep impedance matched? or just series resistors?
That's a great question and I've passed it on to RGC, I'll reply back if I hear anything.
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Xer Xian
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Xer Xian »

Does RGC employ impedance-matched cables and connectors to begin with? I thought that was the main difference between RGC and RCA cables. (Whether that's worth the extra cost though, I don't really know)
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by citrus3000psi »

maxtherabbit wrote:
are there full attenuator networks to keep impedance matched? or just series resistors?
They are full networks. :wink:
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by maxtherabbit »

citrus3000psi wrote:
maxtherabbit wrote:
are there full attenuator networks to keep impedance matched? or just series resistors?
They are full networks. :wink:
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Decoryah »

citrus3000psi wrote:Yes, RGB max levels are right at 700mv.

The CSYNC also has the serration pulses so it works on the BVM D & A series monitors that lack the vcr button in 480p mode.
Does this mean that you don't need any Extron devices in your chain anymore when using Sony BVM D or A series and this cable. Or was that curve on top of screen partly because of Toro? I know that VCR mode fixed curve for PC Engine, Neo Geo MVS and Sega Master System but didn't help with Dreamcast + Toro. You needed Extron device with serr switch on in your chain. Hopefully you only need this cable now?
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by EnragedWhale »

citrus3000psi wrote:
maxtherabbit wrote:
are there full attenuator networks to keep impedance matched? or just series resistors?
They are full networks. :wink:
I guess you are taking about the RCA cables here citrus rather than the RGC offering?
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maxtherabbit
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by maxtherabbit »

EnragedWhale wrote:
citrus3000psi wrote:
maxtherabbit wrote:
are there full attenuator networks to keep impedance matched? or just series resistors?
They are full networks. :wink:
I guess you are taking about the RCA cables here citrus rather than the RGC offering?
we are talking about the Retro-Access cables, that citrus designed the PCB for
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citrus3000psi
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by citrus3000psi »

Decoryah wrote:
citrus3000psi wrote:
Does this mean that you don't need any Extron devices in your chain anymore when using Sony BVM D or A series and this cable. Or was that curve on top of screen partly because of Toro? I know that VCR mode fixed curve for PC Engine, Neo Geo MVS and Sega Master System but didn't help with Dreamcast + Toro. You needed Extron device with serr switch on in your chain. Hopefully you only need this cable now?
Yeah, no need for the extron box with the RA cable.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Fudoh »

Yeah, no need for the extron box with the RA cable.
that's really nice! If you don't mind me asking - how is this accomplished? Is there an active IC inside the cable to manage the serration pulses or is this done with a passive circuit?
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citrus3000psi
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by citrus3000psi »

Fudoh wrote:
Yeah, no need for the extron box with the RA cable.
that's really nice! If you don't mind me asking - how is this accomplished? Is there an active IC inside the cable to manage the serration pulses or is this done with a passive circuit?
Its a passive circuit. There is a multivibrator ic that gets triggered during the vertical blank period.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by mikechi2 »

Fudoh wrote:
Yeah, no need for the extron box with the RA cable.
that's really nice! If you don't mind me asking - how is this accomplished? Is there an active IC inside the cable to manage the serration pulses or is this done with a passive circuit?
That's really cool! I used a similar method, with a PIC as a software multi-vibrator so it can adapt to different line frequencies, in my Raspberry Pi hat. If you don't mind me asking, how long do you hold the sync line low before releasing it during VSYNC? I have it set to 75% of the line duration but some people were still reporting issues with BVMs.
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opt2not
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by opt2not »

Oh wow, looks like this could be a smaller more compact replacement of my Toro (which I do find a bit bulky).
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by evil_ash_xero »

Hmmm....so, what will this do over the normal SCART cables?
I didn't know what the issues were to begin with.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by nmalinoski »

evil_ash_xero wrote:Hmmm....so, what will this do over the normal SCART cables?
I didn't know what the issues were to begin with.
A few things. First, normal SCART cables for the Dreamcast only bridge one video mode pin to get 15kHz RGBS out of the system. This cable (as well as the ones built by thefoo.83) include a mode switch that bridges/unbridges the second video mode pin to toggle 31kHz (480p) output, which can also be used to trick most 480i-only games into outputting at 480p.

Secondly, and building off the first point, the Dreamcast shuts off composite sync output when in 480p mode, meaning it only provides 480p in RGBHV, which is incompatible with SCART. This cable includes an inline sync combiner that will take that 480p RGBHV output and convert it to 480p RGBS so it's compatible with the SCART connection.

And, lastly, normal Dreamcast SCART cables are not built with fully-shielded coax, and would therefore be more susceptible to things like visual noise and audio hum/buzz.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by dseleski »

It’s worth saying a few other things:

480p is incompatible with SCART for *no good reason*. TVs with Scart sockets, that work with 480p in other modes will not accept 480p over Scart. It’s something to do with standards being set back in the day and manufacturers sticking to those standards. Or maybe it’s to do with making you buy a new TV with component inputs. I suspect the latter.

Most consoles with 480p capability will not output 480p over RGBS as a result of the above. Unless you modify them, that is.

Consoles that output vga can be made to do it externally, by combining the H+V lines. VGA allows for 480p mode so you can do this.

Good scalers ignore the standards that set RGBS over Scart at 480i (there’s no real reason for it after all!). OSSC and Framemeister work with 480p RGBS over Scart.

The 480p mode will not work on SCART compliant TVs.
The 480p mode will, however work on scalers and 480p compliant rgbs monitors. These are the solutions used in the USA, so, no worries!
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by fernan1234 »

Yep, SCART connectors can pass anything along up to 1080i, right? They can also pass sync on green of course (PS2, some other consoles with mods), just need to set the monitor's sync accordingly.

BTW, I'm hoping that we'll also see a DE-15 option for this cable besides the SCART and BNC ones.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by nmalinoski »

fernan1234 wrote:Yep, SCART connectors can pass anything along up to 1080i, right? They can also pass sync on green of course (PS2, some other consoles with mods), just need to set the monitor's sync accordingly.

BTW, I'm hoping that we'll also see a DE-15 option for this cable besides the SCART and BNC ones.
Yes, SCART can physically transport pretty much anything up to 1080p (although analogue 1080p is not widely supported; Xbox 360 and PS3 can manage it), probably slightly more; but SCART devices generally don't support more than 480i/576i over RGBS.

Some devices can transmit 31kHz+ using RGsB and/or YPbPr over SCART, but I think few video processors and displays will actually know what to do with those signals, and they probably ignore RGsB/YPbPr, because they [purposefully] do not send any sync signal on the sync line.

I've read a rumor or two that suggests that 31kHz+ signals sent to a 15kHz-only display can damage that display, which might explain why the PS2 won't output 31kHz+ RGBS and why the Xbox, Xbox 360 (I think), PS3, and Dreamcast purposefully disable 31kHz+ when using a SCART cable, though you could still send 31kHz+ to one of these displays with YPbPr, which wasn't addressed.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by maxtherabbit »

Everyone needs to remember that the "sync line" on SCART is not a sync line at all. By the spec, it is a composite video line that just so happens to be used (secondarily) for sync in the context of RGB SCART

There is no such thing as 31kHz CVBS so not tolerating 31kHz CSYNC in its stead is no surprise
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by evil_ash_xero »

So, is this useful (other than the shielding) if I just have my DC hooked into a 480i TV?
Any picture improvements?
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Kez
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by Kez »

If you can't use VGA mode (480p) there aren't any compelling reason to get this, unless your current cable is terrible quality and you have a noisy image.
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Re: Retro-Access Releases Dreamcast 15Khz/31Khz Scart/BNC Ca

Post by the Goat »

evil_ash_xero wrote:So, is this useful (other than the shielding) if I just have my DC hooked into a 480i TV?
Any picture improvements?
This product will not help you in any way, if your display is limited to 480i.
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