C64 S-Video cable – the easy way, and with no SCART

I made another C64 S-Video cable for a fellow Commodorist. Instead of using SCART, this time I made the cable as an actual S-Video lead, which admittedly is more universal than the SCART connector. Also this way it doesn’t take that much effort to make the cable.

This time I present you step-by-step instructions on how to make the thing. For more theoretical approach and details about the wirings and components, check the other post where I made the SCART cable.

I think the best and easiest way to make a cable like this is to use an ordinary S-Video and audio leads. And that’s what we’re going to do here.

Here’s what we need. An S-Video lead, an ordinary audio cable with RCA male connectors, an 8-pin DIN plug for the C64 Video port (check the other post for connector type details) and a 330 ohm resistor. Additionally you might need some heat shrinking tube, and of course, a soldering iron plus some solder, and tools for wire stripping and cutting. Not to forget a continuity tester or multimeter.

By the way, paying some attention to the DIN plug quality is worthwhile. The better ones have pins that are hollow inside, like small tubes. It’s much easier to solder the wires into those than onto pins that are solid, and only have a shallow pit on them.

First, cut the S-Video and audio leads to desired length. If you didn’t spare on the cable lengths, you have the leads for to two cables, woo!

Then, if you do like I did, and tie the video and audio leads together using stubs of heat-shrinking tube, slide them on the cables now, before doing anything else. Also the DIN plug cover should go there at this point!

Next, strip the wires. Then use your continuity tester or multimeter to determine which wire is which in the S-Video lead. There are two ground lines and one wire for Luminance (intensity, “brightness”) and one for Chrominance (colour). S-Video plug pinout you’ll find e.g. on the Wikipedia page. Don’t get mixed with male and female pin arrangements!

In my lead, blue and yellow wires were ground – which is for chroma/luma doesn’t really matter, as there is only one common ground point available in the C64 video port. Green wire was luminance and red chrominance. Apply solder to the exposed wires, and attach the 330 ohm resistor to the chroma wire. Notice how the chroma wire, the one with the resistor, is a bit shorter that the others. This helps in putting the connector together later on.

Now the wires have been prepared. Video ground wires are tied and twisted together, like the audio cable shielding.

Next I’ll be using this ingenious fork pin to connect the ground wires into it! Why? Because the fork pin doubles as a connection between DIN plug pins 2 and 5 and makes it easier to solder the wires onto the plug.

And why am I connecting pins 2 and 5 together you wonder? Because that’s a simple yet effective noise reduction mod for your Commie! Pin 2 is the ground pin, and pin 5 is audio in. Read on about the details on that other post.

You can prepare the fork pin from e.g. cut resistor lead. Prepare it so that you can just insert it onto the pins 2 and 5 of the DIN plug.

Here we have all the cable wires ready to be soldered onto the DIN plug.

Let’s start with audio wires. A stock C64 outputs mono audio, so we solder both audio wires to pin 3, audio out. In case you happen to have a stereo-SID setup, the otherwise unused pin 7 can be used for the second (right) audio channel. Why pin 7? Again, check the other post.

By the way, I found out I could use a desoldering braid package to hold the DIN plug firmly in place while soldering. Best discovery in ages!

Next up the chroma line, the one with the resistor. Insert and solder the resistor lead to the pin 6 in the middle of the plug. I also put some heat shrinking tube around the chroma resistor to avoid any risks of shorts inside the plug.

Then the luma wire to pin 1, piece of cake!

Finally, the ingenious fork pin into it’s place. Push it all the way in and secure with solder.

Now that all the wires are soldered in place, make sure there are no shorts between them. Then the plug can be put together. If possible, the tinfoil or wire shielding found in S-Video and audio leads can be connected to the metal frame of the DIN plug. You can e.g. bend them backwards and squeeze them under the metal part that extends from the plug frame and holds the cables firmly so that there is no strain to the wires itself.

Lo and behold! It’s a brand new S-Video cable for the C64!

As a nice surprise, the image quality is even better with this cable than with the previously made SCART cable. The discussed checkerboard pattern is much lesser, almost gone, and the picture is more stable. I’m not sure what makes the difference, but it might be because now I’m using an actual separate S-Video cable instead of a generic signal cable. Less signal cross talk maybe? Also the chroma resistor is now located right at the C64 video port and not at the other end of the cable.

Anyhow, the output is very satisfactory! Now go make yours.

Some comparing shots

The following photos have taken from the same plasma-TV than the previously taken picture quality shots. Once again the pictures are otherwise unmodified, but this time I have re-saved them with lower jpeg setting to cut some excess file size. I’ll  post these pictures as-is, for those who are curious.

First up, the DIY S-Video cable we just made:

Now, the previously made SCART AV cable in S-Video mode:

Then, for comparisons sake, an S-Video cable I have bought years ago from an on-line shop that sells all sorts of Commodore items. This cable is very similar to the DIY cable described in this post, and probably build using the same principle. But, this cable does not have any resistors nor noise reduction mod for the audio. However, the picture quality is almost identical to the DIY SCART cable above:

Please note that the left image looks smoother than it is due to slightly shaken camera…

And as a bonus, the DIY SCART cable in composite video mode:

48 Responses to C64 S-Video cable – the easy way, and with no SCART

  1. Anonymous says:

    what is that blue “ball” with “Made in USA” words where you plug in din connector while soldering?

  2. Lars Wadefalk says:

    I have to redo the cable, even if it worked, sort of. First I managed to forget to insert the DIN casing before starting to solder, genius. Then my solder tip was a little to clunky so I melted plastic on the DIN. Some pins got loose. Only very short solder time on that thing before the plastic melts. I tried it out anyway, got both picture and sound after jiggling a little. But I have some visible vertical bars in the picture background. Its probably some slight short in the cable. First attempt looks like crap, but once I get rid of a silly plastic joint on audio cable and do the other things right I think I’ll have a nice cable too. Thanks for your superb guide ilesj!
    BTW, there is some metallic shielding going inside the S-VHS cable, should that be in contact with the DIN casing, or should it be soldered together with the grounded cables? Or should I just cut it off?

    • ilesj says:

      Hello Lars,
      Yes, the shielding inside the S-Video cable should be connected to the DIN plug casing if possible. Cutting it off or connecting with the ground does not do any harm, but connecting it to the casing is the ‘correct’ way.

      Vertical stripes may appear even if there is nothing exactly wrong in the cable. If the stripes are very dense, or close to each other, it’s probably the phenomena I referred as checkerboard pattern, best seen in the second pair of TV screen shots. I can’t explain why that happens, but it’s something that C64’s video signal does with many TVs. Trying out different resistor values may improve the picture with your setup.

      Another type of stripes, or bars, that probably will appear with an S-Video cable are alternating light and dark stripes that are about one character away from each other. This is an interference that the C64 itself does. Those stripes have always been there, but with a good quality cable they become (more) visible :)

    • DIN plugs were my first introduction to soldering, when I had a C64 myself. And it almost got me to hate soldering and give up playing with electronics. These plugs, especially the cheaper ones, are hard to solder right, and always melt out of shape. But you can usually get them back into position by reheating that pin and wiggling it with pliers until it sits right. I can solder really tight SMD chips without problem, but still not DIN plugs – to this day I hate the things, and I just opted to buy a ready-made C64 S-video cable instead of making one because of this.

    • ilesj says:

      Yeah, the cheap DIN plugs are… nasty. Things are so much easier if you are able to source the kind of type I used in this tutorial – with hollow pins where you can push in the wire or components you are soldering.

  3. Lars Wadefalk says:

    Ilesj, thanks for the answer!
    I think it is the latter effect that I reacted to, the alternating vertical light and dark stripes, maybe a little more than one character away from each other. If its that strange interference from the c64 that you explained (or 128 in my case), I better go hunt for a crappy cable then, I guess :)
    I had a little trouble getting hold of the right DIN-type also, so I did what you suggested and cut off the two unnecessary 5V pins. But when it came to the soldering it was probably my solder tip that was too fat, or I didn’t solder with the right technique. Now I suppose the best thing is to pre-solder the cable (strip it very short), stick it in the pin and then kind of smear on some solder (quickly) on the outside until it sticks. Well well, I’ll probably manage sooner or later. I’m a software guy, painfully enough to admit, I’m not that good with my hands.
    I haven’t found any nice guides for a RGBi cable though, but I realize it’s probably much trickier than the S-VHS.

  4. Juri says:

    why the 330 ohm resistor to the chroma wire?

    • ilesj says:

      The chroma signal that the C64 outputs is not exactly S-Video spec, and it may cause defects in picture on some TVs. The resistor weakens the signal which improves the picture quality. Or at least it doesn’t make it any worse. You can well try a cable with and without the resistor, or with different values before final assembly.

      Compare the first and third pair of display pictures to see the difference on my TV. First pair of pictures is this cable with the resistor, and the third pair is a similar cable without the resistor.

  5. Juri says:

    hello i’ve done your c64 s-video cable, but unfortunately video output is very disturbed, i supposed was video circuits in c64 but i tried 3 different c64’s and a c128 and the disturbs are the same..
    any clues please?

    • Juri says:

      i give you some more info, i tried a c64, a c64c and a c64g, plus a c128. the s-video cable i used was differend than the one you used, it is composed by 2 wires only, either with shielding inside, so there is one shielding for luma wire, one shielding for chroma wire and finally the shielding of the entire cable.. i connected all shielding toghether, then i connected to pin 2 of c64 side and to the metal frame too… thanks again

    • ilesj says:

      Double-check the connections from assembled cable. Make sure all pins are connected correctly and makes a good contact. Also check that any of the different signal pins are not shorted.

      Rule out the possibility that your TV is not compatible with the C64 ‘S-Video’ signal. Check your email for more details!

  6. HI
    I’ve done your cable, but there is no sound neither video. I’ve double-checked all the connections plugged again and nothing changed. Any hints?

    • ilesj says:

      Hi,
      1. The cable. Double check the cable connections using a multimeter. Refer to the connector pinouts of both ends, and verify that everything is connected correctly using a multimeter or continuity meter. Also check that there are no shorts between the pins or wires.
      2. The computer. Is your Commodore working? Do you get a picture from the machine using some other display cable, e.g. the antenna lead? A broken C64 often produces just a black screen. If television shows just a black screen instead of “no signal”, this could be the issue. There is also a fuse inside the machine – if it has blown, you get a black screen on most C64 models.
      3. TV/monitor. Is the television AV input set up correctly and compatible with an S-Video signal? Have you been able to get a picture from some other S-Video source?

      The issue must be at least one of these three. Check one by one and possibly rule out options by testing with different machine/TV/cable. Hopefully it’s not a Commodore trouble shooting issue!

    • Ok, thx i’ll check it

    • Ok, so I checked connections, there are ok. Commodore is working fine on antenna lead. I think that It’s TV. It’s not compatible with S-V signal. For now i’ll be using antenna lead. Thanks for help!! :D

  7. Update: I’ve soldered off the resistor, now there is some video, but it’s very disturbed and i can’t even recognize letters. When i move the S-V plug around there are some colors and screen is blury.

  8. uncletom says:

    I’m going to make only a composite video cable for the 5 pin din connector: shoud I connect the din metal frame to tinfoil/wire shield? If the answer if yes, on the other side should I connect it on the video and audio ground?

    • ilesj says:

      The DIN plug; yes, exactly. That’s the correct way.

      On the RCA plug side; if there is another ground wire in addition to the wire shield, then no. If the wire shield is the only ground wire in your cable, then yes – the grounds of both ends should be connected.

      In this S-Video cable, the S-Video lead’s tinfoil is connected to DIN plug frame only, and the S-Video signal ground wires to the DIN plug ground pin. The audio lead wire shield is connected to DIN plug ground pin as there is no dedicated wire for ground, only the shield wiring.

  9. Enrico Casio says:

    Hello,
    I have a Roland sampler with the following output: https://www.gearslutz.com/board/attachments/electronic-music-instruments-electronic-music-production/292797d1337502896-roland-s750-s550-s50-monitor-stuff-rgb_moni.gif

    I’m looking to hook it up to a commodore 1701 monitor with Chroma/Luma input on the back and composite on the front. Any idea if this would be at all possible?

    Cheers

    • ilesj says:

      Hi – According to that pinout, it seems to be TTL RGB what your sampler outputs. That is digital 1 bit per channel video signal. I’m not really familiar with that, but there’s no luma/chroma nor composite available from the sampler according to that pinout. You need a monitor that is compatible with that TTL RGB signal. Old PC CGA monitors may be compatible, but I’m not 100% sure about that, either.

  10. foxmark says:

    Thank you very much mate. This post helped me a lot. Well done

  11. Rocky McCleary says:

    Hi! im making an Composite version of this cable. I don’t want to waste any cable, so could i tie in the second audio lead to the first to give the illusion of stereo?

    • ilesj says:

      Yes. This cable does that exactly, but if you want to save cable, you can connect the second audio plug at the RCA connector end (essentially split the audio lead before the left and right audio plug, or connect two audio plug in series). Please note that AV connector pin 4 is composite video. Pins 1 and 6 are not needed for composite cable.

  12. Phil says:

    Great instructions. The picture looks much clearer than with the rf output. I have quite bad colour bleeding though (eg any white blocks on a black background have red and green vertical lines down their sides). I only have one TV with a svid input so I can’t try another TV right now. Any ideas would be greatly appreciated 😁.
    Phil

    • ilesj says:

      Thanks! My understanding is that the unwanted vertical red and green components appear because of color and brightness signals mixing into each other. And the C64 really leaks the color information into the luminance signal. Check the last pictures on my other post https://ilesj.wordpress.com/2012/03/30/c64-av-cable-theory-and-practice/ I suppose the picture crt-luma.jpg is similar to what you are getting?

      And of course some TVs handle the messy signals worse than others…

      To fix this I would try to add or replace a resistor with higher value to the croma line and see if that helps, e.g. 470 ohms or more.

    • Phil says:

      Thanks for the suggestion on the resistor. I’ll try some higher value resistors when I get a chance later this week.

      FYI the colour leaking on my C64 is much worse than the photo in the linked article.

      I’m actually wondering if the chip that renders the video is faulty, or maybe the joints between the chip and the motherboard need re-soldering. The colours are badly washed out and are nowhere near as good as many of the photos you’ve posted. And this is the same on the RF output (washed out but with slightly less colour leaking).

      Also, both the RF and the video outputs go into an odd cycle after the C64 has been on for around an hour where the picuture breaks down every 5 seconds (this makes me suspect a dry joint as I know electrical connections can behave like this once they’ve warmed up). Not sure if re-tinning the joints would improve the colours though – I think maybe my old C64 is just showing its age! :(.

    • ilesj says:

      That’s a possibility too. Although the VIC-II chip is always seated in a socket. You could try to re-seat the chip and see if that helps. If the pins of the chip (or socket contacts) seem corroded, try applying some contact spray.

      If the video chip turns out to be borked, not to worry. Replacement chips can still be found from dedicated sellers. Just make sure to get the right version. Just like with SID chips, the 65xx and 85xx series of VIC-II chips run on different voltages, and therefore are not interchangeable.

    • Phil says:

      I had time this afternoon to do some experimenting. I put a variable resistor on the chromo wire and oddly it made no difference at all. So I cut the chromo wire and again there was no change to the Picture (still in colour, with bleeding, all from the lum wire only). I double checked (and checked again!) that I’d wired it according to the Wikipedia site and the pin outs for the horseshoe D plug on your scart instructions page and it was definitely wired correctly. So as an experiment I swapped the lum wire from its original pin across to the composite pin (leaving the chromo wire cut) and the picture is now vastly improved (slight checkerboard pattern but no colour bleeding whatsoever).

      I suspect that the svideo port on my TV may be wired wrong. Or it’s only happy with composite. Or the chromo / lum pins in my C64 aren’t outputting a good signal.

      Also, using the composite wire has vastly improved the colour output (it looks like the photos on this page now).
      Thanks,
      Phil

    • ilesj says:

      Phil,
      Are you using S-Video to SCART adapter to connect the cable? First things first, are you sure your TV accepts S-Video? Not all TVs have S-Video inputs, and especially new TVs seem to be missing S-Video input completely. And with older sets, there’s usually two SCART sockets, and only one of them can take S-Video over the SCART connector. Check your TVs specs.

      What you describe sounds exactly what one could expect when using an S-Video lead with S-Video to SCART adapter on SCART input that does not take S-Video. As composite video and S-Video luminance use the same pin in SCART connector, you are essentially feeding luma signal (with some leaked chroma signal) into composite video input. Result is exactly that: sharp picture, but bad colors and terrible color bleed.

      Cutting the chroma wire making no change strongly suggests that your TV is not even trying to use S-Video (luma + chroma) signal as its input.

    • Phil says:

      I think perhaps this is my face palm moment. You’re right (the TV input does use an adapter and this does go via scart). I can’t believe I didn’t think about this before I started making up the cable! Oddly I’ve used other svideo devices (our old video camera being a good example) on this TV and never had any issues. I think my only other svideo option is to route the picture via an old AV amp that I have in the attic which I know has svideo inputs. I’m not sure what it outputs though (may actually only be composite as it’s circa 1994). Failing that I’ll live with composite for now. Thanks loads for your help – it’s been very much appreciated.

  13. Mogamat says:

    Thanks man this site is great and you make it very easy to understand what you need to do Thx bro.

  14. Juan Walls says:

    A strange thing I noticed is while the composite video image is of much worse quality because of the jagged borders and bleeding between colours, the areas with solid colour are very stable with no chequerboard pattern at all, while in the S-Video signal the colours although with well defined borders, are not so solid. Chequerboard pattern is evident in the SCART cable and not so obvious in the miniDIN cable but still visible.

    • ilesj says:

      Hi – yeah, your observation is spot-on. My understanding is that the pattern is a result from chroma noise in luminance signal. That is, the color information leaks into the brightness signal causing that pattern in _brightness_. The pattern also changes depending on the color, in blue it happens to be like checkerboard. On red colors the pattern appears as vertical stripes – at least on my TVs. Note how grey colors are free of the pattern; no color information to interfere there.

      In composite video these two signals are combined into one signal anyway, and composite video’s horizontal accuracy is worse than S-Video’s which effectively smooths out this pattern – or at least that’s what I think.

      The leakage would also explain why the miniDIN cable performs better – it’s an S-Video cable designed to carry these two signals. In a generic data cable (as used in my SCART cable) the signals most likely have more cross talk which makes the chroma leakage worse.

      Having the added resistance at the C64’s end of the cable and experimenting with different values, or even variable resistor, might get you rid of the pattern altogether.

  15. jdryya says:

    Just finished building my cable today. Unfortunately, I am not getting a picture at all. I used a 300 ohm resistor in my build as I initially followed a guide from another site. The subject of the wattage rating came up when I purchased the resistors. I believe they are either 1/4 or 1/5 watt. I trust that should not be a problem. I confirmed continuity on all connections and also did your Audio In ground. I found a good source for 262 degree 8 pin DINs but they had the “cheap” non-hollow solder points. I was able to make the connections despite that but I see that hollow ones would be much easier. In addition, solid core cables would help too. I had stranded copper for my grounds and it was a bit of a pain to group together.

    Can you share a link to the “better” 8 pin DIN connectors you used? I have not found any inclusion of this spec on the sites I found.

    • ilesj says:

      Hi there! 1. Do you know for sure that your C64 is fully working? A broken machine typically produces just a black screen (a picture comes up, but it’s just black).
      2. Does your TV or monitor have an S-Video input socket, or are you using some adapter to connect the cable?
      3. Did you check the connections for short circuits? I.e. all the pins against each other.

      Resistor wattage is not a problem, 1/4 is fine, but it can be more or less. There’s hardly current running through video cable.

      The DIN plugs I used I got from a local electrics store. The clerk recommended the better ones :) The link you posted looks good!

  16. jdryyz says:

    I believe I figured out the problem but have not yet tested it. It was a simple matter of getting orientation of the MiniDIN4 incorrect. I need to swap a couple of connections. :) Thanks for you help!

  17. jdryyz says:

    Yeah, my goof. I switched the Luma & Chroma pins by mistake. :) Working fine now, but sadly, did not solve my problem with my Sharp LCD. I think it is just some quirk with the TV. The cable also works with my home theater AVR and 4K TV. I am going to get some better quality DINs and redo the connections, however. It got a little messy in there after the fix I just did.

    • ilesj says:

      Glad you worked it out! Make sure the Sharp has S-Video input. If there is the 4-pin mini-DIN plug labelled ‘S-Video’, then for sure. But if you need to use some adapter, such as S-Video to SCART, you need to make sure the input you’re using really supports S-Video.

      If S-Video input is available but doesn’t work with C64, it may be because of picky TV. C64’s “S-Video” is not exactly within the spec…

    • jdryyz says:

      Oh yes, the Sharp mostly certainly has an S-Video input. It is just picky about what it is being fed, I believe. I am starting to recall that it may have also had a similar thing happen with a laserdisc player I tried to use. I do not think there is anything wrong with the C64 output/cable at this point. The cable works fine with my home theater setup (different TV). I may have not even needed the resistor hack. Then again, I do not yet have one of those S-video to VGA converters. That is when the resistor hack could be necessary.

  18. euirgi says:

    Hi, if I want to make this cable, a standard 6pin DIN connector should be fine, right? Pin 8 is not used and 7 is only for stereo?

  19. Anonymous says:

    Hi! I just made the S-Video cable for my C64 (only the video part at the moment, I will add the sound later). When I connected the cable in my TV my jaws fell to the floor!After all this garbled, noisy blurred image I was getting through the RF port, this new clean crisp signal is a dream!I would never believe that the C64 could produce such a video signal!!!
    Thanks for the instructions!!
    I am going to make one for my Amiga too because the situation there is unbearable. I believe that the result will be equally good!
    Thanks a lot!

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