Best way to get Japanese Saturn working well on an HDTV?

Discussion in 'General Sega Discussion' started by MarzSyndrome, Aug 9, 2013.

  1. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    So here's the gist. Since four years or so ago, I've possessed a modchipped Japanese Model 2 Sega Saturn with switchless modifications to adjust region and 50/60Hz output, purchased from Console Passion. I saw this as an ideal replacement for the old European Model 1 Saturn that was also modded, but only accepted original discs and not CD-Rs (oh, and used full-on switches as well).

    Having recently got it out again, I noticed that the biggest problem was that I could not get 50Hz mode to work properly on either of the 3 HDTVs in our house that I've tested. There's the smallest one - the Goodmans GTVL20W7HD - then the "Murphy 32883 IDTV HD DVD" (so obscure it seems that I can't find anything resembling a website and/or a picture for it), and finally the big lounge one - the Samsung LE37S73BD. All have seen mixed results with the full spectrum of video modes available through SCART. With the Goodmans, 50Hz would only output in monochrome. With the Murphy, it would display in colour but be very erratic, having a brief "spasm" every few seconds or so, which is noticeable enough to make it unuseable for proper gaming. And with the Samsung, it would display in very washed out or oversaturated colours and look generally ghastly, and the output would still be unstable and try to reset itself often. I actually possess a fair amount of Saturn SCART cables acquired over the years, to the extent that I can't even tell if any of them were originally for the PAL Saturn. Yet regardless of which cable I use, I get the same disappointing results.

    So googling around, I thought I'd try my luck with a SCART-to-HDMI converter box. I bought this one in particular, and tried it out for the first time today. I discovered that quite a fair amount of my cables wouldn't display anything through it, but a select few did, with one in particular displaying the best results ever....... provided I stick with 60Hz. Which leads to another problem I'll mention later. Anyhow, I tested this with the Goodmans and Murphy TVs to date since I am unable to access the Samsung TV for likely the rest of the evening. Neither of them could give a satisfactory 50Hz performance, even with the one awesome SCART cable I used. I'd literally see the screen for like a split second before the picture gives away and it desperately tries to get it back again, only to once again only last a split second. During the brief moments where it was visible, I could see that the Goodmans would still only be able to output it in monochrome even if it worked. Murphy on the other hand got it in colour. Overall, I can imagine that the "spasming" problem I mentioned before is affecting the TV/box enough for it to keep killing the display on a consistent basis.

    Thinking about it, chances are all of this is an issue with the simple fact that my Saturn originates from Japan. Should I be trying to get proper Japanese output cables for it?


    I should probably mention btw: the key reason why I'm not so keen on just doing everything through 60Hz is that I seem to encounter the "overscan" problem where bits of the top (and occasionally bottom) are cut off. The only thing I've tested this with to date has been the little Mario game included with the C4 2006 Contest CD (which you can find at The Iso Zone for those interested). I thought HDMI would allow the Murphy and Goodmans at least to adjust the screen position manually, but I guess that's a VGA-only thing. *sigh*
     
  2. dsrb

    dsrb

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    Not to hijack your thread, but I had issues with my Japanese Saturn seemingly being 'deinterlaced' or something by all TVs, except two Sony Trinitron CRTs--despite the fact that it wasn't interlaced in the first place--which made it interlace horribly during movement. Have you seen anything like this? I've never heard any explanation of why this might have occurred, caused by the TV and/or the particular Saturn itself, so if people are going to get technical here, I'd appreciate if they could help with this question too.
     
  3. GerbilSoft

    GerbilSoft

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    This usually happens if you're using a composite video SCART cable, not an RGB SCART cable. The reason for this is because older consoles used a single crystal oscillator to derive all the frequencies used in the system, and this oscillator has to be an exact multiple of the color subcarrier. (NTSC is 3.579545 MHz, PAL is 4.43361875 MHz.) These subcarrier frequencies have to be super-precise; if it's off by even a tiny bit, you'll end up with either no color or unstable color, as you've mentioned. Solutions are to get an RGB SCART cable or to replace the oscillator with a PAL frequency oscillator. (Former's probably the better option.)

    I have a Sony DSC-1024HD scan converter that does the exact same thing. The problem is some TV manufacturers think that "240p" never existed, so they automatically assume that 15 kHz is interlaced. Unfortunately, I don't know of any way to fix this. (Interestingly, I also have a Sony PVM-20M4U professional CRT that handles 15 kHz non-interlaced just fine.)
     
  4. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    I'll admit I haven't tried to pay attention to interlacing so far, mainly because I'm more concerned about getting both video modes on a modchipped Saturn to co-operate perfectly on a UK HDTV setup.

    To those people who found the first post tl;dr, I basically want any solution that will leave me with a working 50Hz mode *and* also provide workarounds for overscan.

    Grimly, it appears none of the three viable TVs in my household provide overscan options. I read the manual for the Samsung TV to see if it'd be any different, but no cookie.

    I'm pretty damn sure I went out of my way first time round to buy an RGB SCART cable after reading up on it back then. Unfortunately my one good SCART cable has no logos or text on it to determine the type, and I don't fancy the idea of opening the thing up either just to see what kind of cables they are, particularly as it works pretty well in 60Hz in its own right. I could bite the bullet and buy another one, but could you recommend anyone in particular who's confirmed to sell genuine RGB cables?

    As for the overscan thing, I'm starting to think that maybe I should try getting a SCART to VGA converter instead, if HDMI is incapable of providing manual adjustment options...
     
  5. GerbilSoft

    GerbilSoft

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    If you have a multimeter, you can check that the RGB pins on the Saturn side match up to the RGB pins on the SCART side.

    Saturn: http://www.gamesx.com/avpinouts/saturnav.htm
    SCART: http://en.wikipedia.org/wiki/SCART

    Also, some TVs might only support RGB on specific SCART ports, while other ports might be composite and/or S-Video only. Check the TV to make sure the port the Saturn's plugged into supports RGB, and make sure RGB's enabled in the onscreen display (provided the onscreen display has an option for it). There's a not-quite-standard addition that replaces some RGB lines with S-Video, so it's possible that the TV might be looking for an S-Video signal, and since it doesn't find it, it falls back to composite.
     
  6. Usually only the first (if multiple are present) SCART connector supports RGB.

    Please make sure:

    1) The RGB lines are properly connected (open the scart connector, usually quite easy) and none of the resistors and/or capacitors have loose leads
    2) Make sure all the ground pins are connected properly
    3) apart from that your TV might just not support RGBScart anymore. An SVideo signal is an after thought but supported by most SCART capable devices (Since it has existed since S-VHS came out), where the chroma signal is put on pin 15.
    4) Check pin 16: AV/RGB-switching signal: 0..0,4 V– (low = FBAS), 1..3 V– (high = RGB) @ Z = 75 Ohm -- and also pin 18 which is the ground pin for that signal.

    (Also, I have checked any my 2012 SAMSUNG Plasma TV does not support Y/C on SCART anymore, while my 2006 LCD TV from SAMSUNG does... Both support RGB SCART though.)
     
  7. Meat Miracle

    Meat Miracle

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    A Japanese Saturn, when set to 50hz mode, will output a nonstandard (?) NTSC50 colour signal which very few devices can handle, hence the black/white picture. My Panasonic Viera can't handle it for sure. I have a very old Sony projector that can do it on paper, but I haven't actually tried it.

    Scart RGB should, work fine however, but do note that for Japanese and USA Saturns you need either the Japanese RGB21 cable (which has different pinout from regular Scart), or an aftermarket cable from ebay.

    The forced deinterlacing is because the 240p signal used in old consoles do a trick of some kind, forcing the raster beam to not switch between odd and even lines every other frame. HDTVs (and in fact almost any digital displays, including old projectors) don't do this and treat everything as interlaced; and most HDTVs have deinterlacing forced on such signals.
     
  8. MarzSyndrome

    MarzSyndrome

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    Ow, my brain, this is all too technical for my liking! >.<

    Would it help at all if I took photos of the good SCART cable I have and the respective in and out ports on the Saturn and HDTV(s) in question?

    So does this mean I'm more or less boned? I could alternatively live with 60Hz, provided it didn't affect PAL games too negatively, and more importantly if I can find a solution to the overscan problem.

    So something like this would be suitable? Doesn't mention RGB21 but it does state that it's for Japanese Saturns. Bit pricey for a single cable though.


    Another question: has anyone ever been able to get the Saturn to work with a SCART-to-VGA conversion or anything of the sort?
     
  9. No you don't, his TV is still SCART, not RGB21, and the pinout at the console is the same.

    EDIT: OK, fuck me, it's not.

    This should do the trick. the video cable is missing the switching signal that goes to pin 8. Very easy fix.

    http://www.mmmonkey.co.uk/ntsc-saturn-and-pal-scart-leads/
     
  10. Meat Miracle

    Meat Miracle

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    erm, which pinout do you mean? The Saturn has an official RGB21 cable in japan, so it works for sure on Japanese Saturns, you just need a pinout converter for RGB21 -> Scart (or even open up the connector and manually rearrange the pins). RGB21 and Scart use the same connector, just with a different pinout.

    PAL and NTSC Saturns differ in the a/v pinout, PAL machines have c-sync removed in favour of a 9v signal required for SCART auto switching. Scart cables sold with the Saturn back in the 90s are wired to use that 9v output. If you put them in a NTSC Saturn, you'll either end up with composite only, or a picture jumping between composite and RGB randomly, as the voltage level of the c-sync signal spikes. That's why separate NTSC RGB Cables are required (since most aftermarket manufacturers just copy the PAL Scart cables design, you need one specifically designed for NTSC machines).

    Since the voltage pin required for RGB switching is not outputted at all when using a PAL Scart + Japanese machine, you can't really fix that in any way unless you mod your console to output voltage instead of c-sync... which is counter productive since some upscalers need that instead of composite input, and if you remove c-sync, you need a sync splitter circuit.
     
  11. MarzSyndrome

    MarzSyndrome

    Everything is going to the beat. Member
    To be honest guys, I think I'd rather just throw my money at some reliable (local) wiring expert to have them make a super-duper magicky cable for me, than attempt to mess with intricate wires and volts myself. =P

    While I was looking around, I decided to watch this video about the XRGB-mini, despite it being something more within the "wallet destroying" range I've been trying to avoid. It looks good. VERY good. But yet I'm still none the wiser as to how well exactly it can handle 50Hz and 60Hz outputs on a Japanese Saturn (especially a console which can switch between both at will), and how well it attempts to show the full screen and not cut off the top/bottom/corners (hence the 'overscan' issue I keep blabbering on about). Is it really worth getting though just for the sake of getting a perfect display output on my Saturn by any means? I mean, sure, I have a PS1/PS2/Dreamcast/Gamecube/Wii to use it with as well, but as of now I seem overly obsessed with getting the very best out of the Saturn specfically, with the TVs I'm currently stuck with. Emulating it on my PC just doesn't really cut it for me.
     
  12. Meat Miracle

    Meat Miracle

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    You can't change the wiring in the cable since the "universal" 5v voltage pin is not connected on the Saturn side of the cable, you'd need to hack out the entire cable to solder that on.

    If you want perfect picture, get a Trinitron CRT.
     
  13. dsrb

    dsrb

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    With apologies again to MarzSyndrome...

    Thanks to you both for the info. But can this explain why the problem occurred only with my Japanese Saturn, not PAL ones, and on CRTs as well as HDTVs? The only TVs that didn't exhibit the 'phantom' deinterlacing were two Sony Trinitron-type sets I've tried. Others, whether CRT or flat, showed the Japanese Saturn all messed up when moving but PAL ones fine at all times.

    I do have an old thread about this, but we never got much further than the differences in pinouts that have already been noted in response to MarzSyndrome. And on that note, I was using PAL SCART cables on the Japanese Saturn because I couldn't find official NTSC ones, only a third-party one that didn't work on any console. I didn't notice any problems due to switching or anything like that, just the interlacing already mentioned. But could the absence of composite sync, or something, explain why only the Trinitrons could display the Japanese Saturn OK?

    And on that note, what magic must the Trinitrons have that all other TVs lack? I tried a good few other sets of various types and brands, and only Sony Trinitrons displayed properly. I know these are good sets, but I can't begin to imagine what the do that's so special that they can circumvent whatever was coming out of that Saturn and confusing all the other TVs.

    Since I've not read about this problem from other people online using NTSC-J Saturns, I ended up suspecting it was something wrong with my specific console, not Japanese Saturns in general.
     
  14. Meat Miracle

    Meat Miracle

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    You can use a pal scart cable with a Japanese Saturn, but it will either work in only composite, or it will go apeshit and randomly switch between composite and rgb, or it might just work. The c-sync signal, to which the RGB selection pin is wired in PAL Scart cables, is not a stable direct current voltage required by the Scart/Peritel standard (it has to be between 1-3 volts; the c-sync signal does not always reach that, so you have problems).
    Some TVs might still work in RGB with it, if they ignore the standard and force RGB on certain ports, or have RGB selectable instead of automatically switching, etc... Also, some scart switchers actually add the required voltage there.

    I'm not sure why your Trinitrons displayed the 240p signals properly; there are quite a lot Trinitron models out there, some may work fine, others might not. I know that the Sony projector I have from ~2000 can't do 240p and displays the interlaced signal, unlike modern TVs it does not force deinterlacing.
     
  15. You know, it would be so much easier to just rewire the cable properly or do the small fix I linked instead of listening to all the half-knowledge Meat Miracle is spewing about
     
  16. dsrb

    dsrb

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    I'm not going to get into whatever argument you two apparently have. I've not seen a need to rewire my cables, which were needed for PAL systems too at the time anyway. And I appreciate everyone providing info, so there's no need to get so possessive.

    I found no drawbacks aside from the interlacing, which I assume is separate. Obviously I had to switch to RGB SCART input manually, but that's to be expected.

    And other CRTs, is it normal that they wouldn't display 240p fine? As I said, I don't remember the same TVs having such problems with PAL Saturns, so is that because they're 288p instead? I'm trying to deduce whether this was a problem with that NTSC-J Saturn as an individual unit, or if it's to be expected from most [edit] PAL [/edit] TVs running any 240p signal. I think your post might be indicating the latter, but I'm not certain.

    Again, I appreciate any info here, so let's not start a pointless argument unless someone posts something that's obviously BS, which I've seen none of.
     
  17. Meat Miracle

    Meat Miracle

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    CRTs should all display 240p fine as far as I know...
    Do note that quite a bunch of Saturn games actually do output 480i; they run in high-resolution. Virtua Fighter 2 being the most popular example. PAL machines have an option to output 512 lines (either as 256 progressive or 512 interlaced), some PAL games were optimized for that (again VF2 comes to mind, but many big-name titles did it too).
    Maybe you just tested your PAL machine with such a game, to get interlacing on a CRT?

    Aside from the c-sync/9v pin on the a/v out, there should not be any difference between any Saturn model as far as the video output goes, especially not concerning interlacing. The only difference is that PAL machines have a 256/512 line mode, but you can do that on a NTSC machine too, it's entirely controlled by the VDP2. In fact if your machine has the 50hz switch, it is already capable of this.

    The monochrome signal is because the TV is using composite signal (it is not auto-selecting RGB mode), and it doesn't understand the 50hz NTSC colourburst signal (few devices do).
    The Murphy is displaying RGB, but its spasming because the RGB select voltage is not proper, due to the aforementioned A/V connector difference between PAL and NTSC units.
    The Samsung is reseting the signal for the same reason, I dunno if it's using RGB or composite with some weird colour mode autoselected.

    You just need a rgb cable wired for a Japanese machine, or mod the console to output voltage instead of c-sync.

    I'm interested in knowing what half-knowledge you refer to; I admit that I'm not up to snuff on how broadcast systems and CRTs work, but I at least know how a Saturn is wired.

    What do you mean by rewiring SCART cables? If you use a PAL cables on a Japanese Saturn, you have no voltage pins taken from the Saturn side, so there is nothing to rewire inside the Scart plug.
    The "small fix" you linked to means opening up the machine, de-soldering a decoupling cap, and thereby removing c-sync out and replacing it with a voltage pin. It is enough to get you RGB with a PAL Scart cable on a Japanese Saturn, but it will lose the ability of the machine to use c-sync, which some displays might actually need (some projectors can take 15khz RGB+c-sync inputs, and I've been told the XRGB Mini works better with that as well). Without that, you have to build a sync stripper that splits composite to c-sync. This is a potential drawback if you plan on using upscalers in the future. Of course it works as a quick and dirty fix if all you want is Scart RGB out for your TV.
     
  18. Finally. There you go.

    PS: Ever heard of switches? For all intents and purposes you can use the QnD tracecut method with a switch depending on what you need, or as this is about RGB simply replace composhit video with C-Sync (or wire those two to a switch). Either way, it's not exactly high tech and done in 5 minutes tops.


    PPS:
    Actually no device that holds strictly to the standard colorburst frequencies (3.58/4.43) can understand that signal. NTSC-50 is actually a perfectly valid signal understood and processed by TVs and capture devices. The problem is that the colorburst is derived from a master clock that is different depending on the region, and if you change to 50Hz in a 60Hz-region system and 60Hz in a 50Hz-region system the frequency is neither of those two. Only extremely rare and expensive equipment which let you freely select the colorburst frequency will display such a signal with proper color.

    There are a few signal types that these are commonly (*wrongly*) referred to. All of these exist as a standard (PAL-60, PAL-M and N, NTSC-4.43) and are not the signals you will get out of the console.
     
  19. Meat Miracle

    Meat Miracle

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    Well if you want to hack up your console you can fix the "problem" in a multitude of ways anyway, but I assume he bought a pre-modded console because he doesn't want to/know how to do that.

    You can select 50/60hz mode on the VDP2, and colour encoding on the CXA video encoder separately - I hooked up a machine with switches on both, and tested all modes with both the 14.31 and a 17.72 master oscillators.
    The signal a Japanese Saturn sends in 50hz mode would be, depending on whether they used JP1/2 or soldered to the lifted VDP2 pin: PAL, 3.58Mhz, 50hz, or NTSC, 3.58Mhz, 50hz. Neither produced composite colour on my Panasonic TV (P42G10E).
    In fact the only setting that produced composite colour in both 50hz and 60hz was PAL + 4.43Mhz. I assume because the TV was compatible with the PAL60 they use in South America.
     
  20. MarzSyndrome

    MarzSyndrome

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    Ok, is an upscaler such as XRGB likely what I need? As in it can handle NTSC50 *and* make the screen area in 60Hz mode fit on any TV properly, with no cutting-bits-off bullshit?