Little Rabbit

Hi Vince42, Yes, I think your TIA is a PAL one, with a single audio output : it is very close other pictures listed on the Atari Compendium :). Regarding the extra figures "8842S", it could mean that it had been manufactured during the 42th week of the year 1988 :). That's a common habit on chip manufacturer ;). Yes, I confirm your VCS is a Vader one, with its black dress :). In my previous post, I forgot to confirm that the RGB mod I was talking about is the one from the Mr Eddy page : I should try it shortly, or design a slightly different version.

Hi Vince42, I'm not a specialist but it is a little bit more complicated than that . I know that SECAM 2600 PCBs are sometimes equiped with an NTSC TIA, other times with PAL TIA. Because the color encoded video signal is not used, it doesn't matter, they both act in the same way (but they DO have a different pinout !). The major different TIA I know are : C0104444D => NTSC TIA (with stereo audio output) C011903 => PAL TIA (with mono audio output) But there's actually a ton of slightly different TIAs out there, depending on factors such as what is its silicium foundry, when it had been manufactured, etc. This page lists all the known variants .

Hi Vince42, If you found those cartridges in France, getting them with this SECAM console for example, there's 99,9% of chance they are PAL cartridges. That's what I would have said to any French owner of VCS cartridges :). And now I have seen your screenshots, I can confirm they are 100% sure PAL cartridges, because you get colors on your screen . Your cartridges would be NTSC ones, the picture you would get of your SECAM console via the RF signal would be black and white (I tested it yeasterday evening with a "Combat" NTSC cartridge). On my TV, I got a solid stable 60 Hz picture (the gameplay is faster ! ?), with other TVs, you might get a rolling picture because it expect a 50 Hz signal only. That said, if you build the RGB mod I mentioned before, then you would get av 8 colors RGB picture even with NTSC cartridges, because with RGB you get rid of the color encoding process that only works for given modulation frequencies . Most of the PAL cartridges shows a little "P" for "PAL" on the top right corner beside the title of the game, on the label glued on the top of the cartridge. You can see it on my Vanguard cartridge on the picture I posted a few days ago :).

Hi Vince42, Not exactly : the TIA you find in the SECAM 2600 can be actually a PAL or a NTSC TIA , it doesn't matter because the electronic doesn't use at all the chroma signal going out the TIA. In the SECAM model, it's an additional electronic assembly that build a color SECAM signal, built upon the 3 levels of luminance, that combined together will allow only 8 "pure" colors. That why the colors are so "weird" and have no relation at all with the original colors. Kindly note that the RGB mod will be compatible with a TV only via a Scart/Peritel plug. It can't be compatible with a VGA monitor because VGA is a complete different video signal (horizontal frequency at 31 kHz as a progressive signal, when the TV is only 15,6 kHz, with an interlaced signal - well, not interlaced on the VCS, but anyway, the frequency is not compatible at all ;)). Yes for sure ! I can make you whenever you want a "gateau Nantais", or a "bar au beurre blanc", or give you the address of several producers of high quality Muscadet ? (Luneau Papin is one of them ! ). Where do you live in France ?

Hi, No : pin #1 of the 6507 is not connected to pin #34 of the RIOT. The NE555 seems to be used to reset the 6507 only. Well, I couldn't say what are the references of the resistors and capacitors involved because I can't read the silkscreen printing without desoldering the components... But the RIOT seems to have a simple RESET circuit made of 1 capacitor and 1 resistor, the ones just next to the 6532 on the right. That could be R201+C211 like on your schematic .

Hi, Oh sorry, I didn't understand you expected a precise answer . Here are pictures of the area : Well, I've looked at it closely tonight, and as far as I can see (without having desoldered the components) there's nothing very exciting about it : it simply looks like a RESET circuit when you power on the console . The NE555 is used as a monostable, its output connected to pin 1 of the 6507 : The other components on the left are related to the Game Select and Game Reset buttons, going to pins 23 and 24 of the RIOT. Tell me if you's like more detailed information .

Hi Vince42, Thanks for having tried to connect your Atari 2600 to one of your TV set ! ? Because your TV is a 16/9 format, the picture doesn't have the proper aspect ratio, but except that detail, everything looks good and normal to me ?. The colors you get are just the "normal" colors you can expect from a SECAM 2600 . I just plugged Vanguard and Pole Position on mine to compare : => I get the exact same pictures with the same colors (1st one in attract mode) : 2nd one in game : And Pole Position : The only improvement you can work on is the sligthly snowy picture : maybe by checking there's no oxydation on the RF plug. If you want a really better picture, you could give a try to an RGB mod, like the one of Mr Eddy : RGB mod for SECAM ATARI 2600. But of course you will still get the "wrong" colors that a SECAM console can only deliver (build from the 3 levels of luminance out of the TIA) ?. As a conclusion, I would say your SECAM ATARI 2600 is in perfect condition and works as it should. Replacing the capacitor you mention can only make it more reliable . Kind regards,

Hi Vince42, Oh OK, I see !... Why don't you take 5 minutes to hook it up to your plasma or LCD TV and start an automatic scanning ? The RF signal of the VCS is rather stable and "narrow" enough to be detected by many modern tuners (much more than other consoles such as pong clones or Videopac for example). In my oppinion, we cannot exclude the possibility that since the beginning we're talking about a VCS in perfect working condition but not showing on your oscilloscope what you imagined you would see ;). I'm kinda kidding but, even if I have myself a little knowledge in electronic, I know by experience that I do not always see what I imagined to see before puting the probe to a given point of the PCB ;). Not later that this afternoon, I was looking at an old console (architectured with the Signetic S2650 + S2637), and the video signal going out of the S2637 chip (video chip of the console) was lees than 1 V, where I imagined it would be a high TTL level around 4,5V. It looks stange, but it is in working condition ! What game cartridge are you using to do your test ? Since you do not have a visual and audio feedback, you'd better take a game that shows a screen full of pixels, with sounds, immediatly after the game reset.

Hi Vince42, I haven't read in details all your explainations, so I don't think I will be able to help you... But I'm asking just to be sure, because the quick reading I did on this topic haven't let me see an anwser to the question that Stephen Moss asked at the beginning, that I quoted above : are you doing your test with a TV that does have a SECAM tuner ? Do you live in France, Poland or Russia for example, I mean a country where the video standard was SECAM and where every TV set had a built-in SECAM tuner ? My question might sound stupid, I know, but your profile doestn't say where you are from :). If your TV is only NTSC and PAL, that would be just normal you don't get any picture from this SECAM VCS ;). Have you tried to connect your SECAM 2600 to different TVs ? Modern tuners have sometimes difficulties to correctly get tuned with a weak RF signal. An old TV, ideally one with manual trimmers for adjusting the channel might give you better results. Yeasterday evening I hoocked up one of my VCS, a Vader VHF SECAM model just like yours, to a SONY TV from the ninetees I believe : with automatic tuning, I first got a snowy rather bad picture. I replaced the RF cable and then it was very good (possibly some oxydation on the RF plug...). @ChildOfCv : I wanted to warmly thank you for the terrific job you did on that reverse engineering for the SECAM VCS ! ?Your schematics are more than valuable ! Kind regards, Little Rabbit