patrickvogt

I think you already found this document: http://www.pong-story.com/GIMINI1978.pdf. There is a black/white reference implementation for the 8610 (first game) and a reference colour implementation by adding the 8615 after the 8610 (between page 20 and 30). Honestly I think the best way would be to first try to get a working black/white compostie signal either directly by soldering to the game chip on the cartridge (I don't know if you can just combine all the video signals and sync similar to the AY-3-8500, the above document contains a list of all the video signals, I honestly didn't read the text fully) or by following the traces on the game cartridge to the pin connector and then on the motherboard to find a (maybe weak) black/white compatible composite signal. I think if this is working you can then go to the next step and search for the color signal (which should be somewhere "behind" the point where you took the black/white signal). Sorry that I couldn't help you much.

Hi, I've bought a faulty SABA Videoplay (German Fairchild Channel F) on eBay and looked inside to repair it. The problem is that the video which is generated from the console is faulty (see picture one and two). I couldn't find anything obvious on the mainboard so far. Everything on the top looks clean. On the bottom side the traces look weird (see third picture). I don't know if this is intended or if this is a flaw of the pcb production? The console is 40 years old, so I think I can't expect that everything looks new and shiny. When I start the console there is a pong like beep at the beginning. In my opinion: -It cannot be the internal ROM since the same happens with a cartridge -It cannot be the power supply since I can mesaure all the voltages (-5V, 5V, 12V) on the Video RAM ICs -It cannot be the RF circuit since then nothing would be shown on the TV. So the faulty video signal is already faulty before the video signal is going trough the RF circuitry. So the only thing which could be faulty is in my opinion the Video RAM (either the Video RAM ICs or some traces / sockets / cold solder joints near the VRAM chips). If I exchange two of the socketed RAM ICs the pattern looks a bit different (see difference between first and second picture) I already ordered new RAM ICs but since I probably have to wait 4-6 weeks until I get them (German custom control), I thought maybe somebody else has a different idea what components/ICs I can check.

Ok, so I think this will be my last 2 cents about this topic. As I already said above: You dont have to wire one of the four bottom pins of the TV TYPE switch to GND since they are already connected to GND (see first picture). And unfortunately I didn't had a spare NOR-Gate, just a spare NAND-Gate . But fortunately I have been attentive during my logic lecture, so I know that NOT(A \/ A) <=> NOT(A) <=> NOT(A /\ A). So if I negate a signal via a NOR- or NAND-Gate is the same piece of cake. (Just put the same signal into both inputs of the NAND-Gate and the result will be the inverted signal) So I used a CMOS IC 4093 (Quad NAND-Gates) and as VCC I used the same +5VDC from the voltage regulator which is used for the AND-Gates in the RGB mod circuitry. Then pin 21 of 6532 goes to the output of the NAND and as input I used the orange wire which I wired to one of the top pins of the TV TYPE switch. So that should help people which doesn't want to have the flaw with the inverted TV TYPE positions for colour and b/w on SECAM ataris. So only thing left is a crappy demonstration video. Here you go:

@alex_79: Thanks for all the useful information about the SECAM atari :-) Ok, today I got some time and looked a bit closer for the hard wired B/W mode of my SECAM atari. 1. I tried the basketball game and looked at the colours in B/W mode (see first picture). Then I had a closer look at the traces from PIN 21 of the 6532. It is directly connected to the GND pin of the cartridge port (see second picture). The good thing is that all the ICs on my SECAM atari are socketed (I hope this english word even exists). So I got the IC6532 out of the socket, then bent PIN 21 about 90 degree to be horizontal to its prior position and put it back in (see third picture). 2. I tried the basketball game again and looked at the colours in Colour mode (see fourth picture). So this all looks exactly as you said. Somehow an inner voice said I shouldn't cut any traces. This way the mod is reversible again. I mean I could also repair a cutted trace but this way it is much easier to return to the initial setting of the SECAM atari. So after that I had a closer look at the area around TV TYPE switch with my multimeter to check for continuity. It seems that on my SECAM atari the lower four pins are connected to each other and go to GND. The upper two pins only are connected to GND if the switch is in its upper position (see fifth picture). So I just soldered PIN 21 of the 6532 to one PIN of the top row of the TV TYPE switch and connected one of the bottom four pins of the TV TYPE switch to GND (as I am writing now this should be unnecessary since the lower four pins of the switch are already conected to GND) (see sixth picture). That will do the job but the only problem is that the switch is inverted now. So Colour position (switch) is B/W position since then pin 21 of 6532 is connected to GND in this position and vice versa. So I'll try to find a spare 4x NOR gate, so I can negate the singal by using the same signal for the same NOR gate since NOT(A \/ A) <=> NOT(A), where A is the position of the TV TYPE switch. Without that James Bond was not playable since it will automatically pause after starting the game. Edit: Hm, after thinking about it. The inverted switch shouldn't be that much of a problem, since it doesn't have the meaning of B/W and Colour on a SECAM atari. And if I pause the James Bond Game (e.g.) with the B/W position of the switch or the Colour position of the switch should be irrelevant. The important thing is that I can at least switch now between those both positions. So last steps are only to remove the flux residue from the PCB and make the mod final (maybe also using a custom PCB, if I have enough time)

So, the parts arrived and I made an RGB scart cable and the RGB mod for the console. First image is Keystone Kapers (PAL) on the SECAM Atari 2600. Second image is Medieval Mayhem (https://atariage.com/software_page.html?SoftwareID=4081) as referenced by SpiceWare before in his Atari NTSC vs PAL vs SECAM page. So next step would be testing e.g. James Bond about the Black and White switch to be used as pause button. But I will probably wait a few days before I investigate this problem.

Here is a short translation. I also think it is just "simulating" a normal joystick (UP,DOWN,LEFT,RIGHT,BUTTON at least for the VCS). Maybe it can also be used on a Genesis/Mega Drive which should have 9 button options in total. The dance mat is working like a normal joystick. Besides an optical display [i think thats the black thing on top] it also contains a 9-pin joystick connector. Through the movement of the gamer every game can be played "actively" [so get up!]. A joy for kids and grown-ups which will gain a whole new target audience for gaming. Compatible with every game [console] which supports a joystick. Only thing I wonder is: This offer also includes a manual and three used game cartridges, which supports this type of input in a perfect way. Honestly, I am not sure if I wanna Tennis with this mat.

Wow, thanks for all the information and espacially the link to the french blog article. I ordered the parts and will do the RGB mod first then. If that works, I will take care of the TV TYPE switch and will try to get "James Bond 007" to pause on this Atari if TV TYPE is set to COLOR. But there is still one question about the circuitry of the RGB mod: Why is he putting the Red (Rouge), Green (Vert), Blue (Bleu) and Sync signal trough an AND gate each? I mean from a boolean/logical point of view, if A is a fixed variable, then A /\ A <=> A (of course this is electronics and not a real boolean environment, where the FALSE and TRUE state are completly isolated/separated). Is this to stabilize/normalize the voltage level of those signals? Just want to understand that part of the circuitry. Best Regards Patrick

Hm, desoldered the mod circuit from the SECAM Atari and soldered it into PAL Atari. The circuit works fine with the PAL Atari. I also posted the question about the B/W video at the German forum where I got the video mod circuitry from. One guy there suggested I should compare the circuitry between PIN 8 and PIN 12 of the SECAM/PAL TIA with the scheamtic of the PAL motherboard here on AtariAge. Definitely the quartz crystal between those pins of the SECAM TIA has a different frequency (PAL(Y201) has 4.43MHz and SECAM(Y201) seems to have 6.5MHz). But maybe I am wrong. I will further investigate this issue. But another question: Even if I would get colour with this SECAM console: A software which uses the B/W switch to change between color and B/W mode (like the Activision Tennis International Edition) will be only shown in B/W on this Atari, right? Since the SECAM console is hardwired to the B/W position and if the software support B/W mode it will always use B/W mode. But probably better to take one step after another.

Hm, The Mrs. Pacman game cartridge is definitely a PAL cartridge, so this can't be the problem. I will desolder the video mod circuit and solder it into my woodgrain PAL Atari to check the mod. Thanks for the clarification on the switch (that this switch is read by the software and no hardware switch at all). I found this post and this guide on the internet and didn't know that the switch position has to be read by the software itself and just will react to the switch position if the software is programmed that way: http://atariage.com/forums/topic/10800-secam-2600/?p=104949 http://www.alienbill.com/2600/101/docs/stella.html#palsecam

Hi, I own a SECAM Atari 2600 system and did a video mod since it has the C011903(PAL)-Chip. The picture looks good. The only problem is that the picture is in B/W and the switch doesn't seem to change anything. I think I've read that the SECAM atari is 'hard-wired' to B/W mode. Does somebody know where this 'hard-wired' B/W-mode on the PCB can be disabled? Best Regards and thanks in advance