RickR

Wow, all excellent info! Thanks! Well in my case, I believe I still have my channel select switch in place on my console and since I removed the RF from it over a year ago to add in the audio input jack, seems as good an option for making it useful again as possible? I will reform the leads on it a bit so I can try and move it further back a tiny bit to make it easier to reach.

The AtariVox will work just fine (the gate input are high impedance and do not affect the levels of the pins), but the pause mod can be triggered while the Atari communicates with the device. Whether this causes issues or not depends on the specific game. The fact that current games work fine doesn't exclude the possibility that future ones might have issues.
 
The SNES2Atari adapter supported, for example, by "Attack of the PETSCII Robots" for the 7800, uses pins 1 and 2 to send the clock and latch signal to the SNES controller. The Savekey uses pins 3 and 4 for the I2C serial data and clock protocol. The "Compumate" for the 2600 uses pins 1-4 on both ports for the bankswitching of the Computer ROM.
There are some roms that use the ports to communicate with a computer serial port, or to drive external devices, and it's possible, for example, to use them to connect two consoles and play multiplayer games that way...
 
 
The 2600RGB mod uses a similar method of "impossible combination of inputs" to add an extra SWITCH on the controller to allow for remote RESET and SELECT switches, as well as an hardware PAUSE (it halts the CPU) and a PALETTE select function.
That proved to be incompatible with the mentioned trackball games (which caused disappointment to the unaware customers), but also in other cases which are less obvious:
e.g. "Track and Field" is unplayable (with a standard joystick, not only with the "Track and Field" controller that allows to press left and right simultaneously) if you have a RGB mod with the extra function wired to the controller port. And doesn't matter if you actually have the extra switch installed on the joystick.  That's because, for whatever reason, the code in the game briefly pulses pins 1-4 LOW in both ports on each frame!
 
My point is that the pins on the controller ports are general purpose Input/Output ones, and the game code has full control over them. Not only different controllers can pull up/down different combination of inputs, but the code itself can drive them directly, even when nothing is connected to the port, and the pause mod cannot tell the difference. The possibilities are infinite, and new games and controller/devices keeps being developed. That's why I suggest to have a switch to disable the function: if you ever encounter a game (or controller or device) that conflicts with it, you can just temporarily turn it off.

I wasn't aware of the AtariVox functions being affected by this? I will have to give that try as one of the other many mods on my 7800 is an Audio input jack that I plug my AtariVox into to be mixed within the console and come out with the rest of the audio so I don't have to connect it to separate external speakers.
But the reason I use Up+Dn is not just because this pause kit also does, but because I originally years ago was using the Left+right combo and the Harmony cart did NOT care for it at all. I do have a diode pair inside my controllers to isolate the signals from each other independently, but the actual SMS kits only use a pair of 220ohm resistors off the inputs.
As for the driving controller and trackballs? I own them, but I never use them on my 7800 as I just don't play any games that use them.
 

Nice mod and very clean job!
A couple of notes:
1- You don't need to wire the second port, but you cannot just leave the inputs of a logic gate unconnected, else they'll show erratic behavior, electrical noise and increased power consumption (especially with HC/HCT family ICs like in this case).
Simply tie "2U" and "2D" inputs on the mod board to +5V if you don't want the pause function for the second port.
 
2- Consider adding a switch to disable the mod (e.g. break the connection between the "PB" output of the board and RIOT pin 21). Else, some controllers such as driving controllers and trackballs will trigger the pause (or B&W switch in 2600 mode) function.
This can also happen when a game uses the ports as outputs: for example, pins 1 and 2 ("up" and "down" in a joystick) are used to interface with an Atarivox, and the RIOT outputs can be set simultaneously LOW by the code while trying to communicate with the device, even if nothing is plugged in the port, and that again will trigger the pause/B&W switch.
 
Given the number of different controllers and devices (and the new ones that the homebrew community keeps developing), and the great flexibility of the 2600/7800 controller ports I/O pins, there isn't a combination  that is really "impossible". There will always be some game or device that will trigger it, so you need to be able to disable it if needed.

Lance,
The reason I don't ask for all of their stuff is because it simply increases the shipping cost too much. Power supplies add quite a bit of weight in many cases and with shipping being what it is today, each pound adds up. I get what you are saying, but in most cases, I've done some troubleshooting with my clients ahead of time to make sure something simply like a bad PSU or controller isn't to blame first. Here is a such an example that happened last night in fact:
Had someone reach out to me through my FB profile for my ITC services. It was recommended they reach out to me to look at having their LCD replaced in their Lynx console so they wanted to know how much that would cost etc. With some questions, I asked why they wanted a new screen. And they stated because their original wasn't showing anything head on and you could only just make out the image when viewed from an extreme angle so they were looking to one of the newer screens installed etc. 
I asked them if anything changed when using the contrast wheel on the system... and they came back about 30min later stating they completely forgot that wheel was there and it was looking like it did originally again and thanked me for my time. I was happy to do that and while I could have insisted they get a new LCD still, it was only being suggested because they thought their screen wasn't working. It was and now they can play it as they wish. 
I would like to think that actions like that, will have them remember me when they might be in actual need of my services in the future so again, I try and make sure the simple stuff has been tried first for my clients before they send it all my way.
 

There is a dedicated blanking pin on the Maria. However, the odd bit is that the pin is only attached to the expansion port bus and doesn't seem to go into anything else within the video circuit. But obviously that isn't the case or there are additional signals being provided by the Maria that effected this that weren't working.
It wouldn't have surprised me if this was always an issue with this 7800 that again, just wasn't really discovered. When playing on a consumer level CRT, that extra info was likely in the overscan and just wasn't noticed.
 

I only request the consoles to be sent in because I have spare PSUs and controllers, plus several different test carts for servicing the consoles. There has only been a few times where something arrived working 100% for me that didn't work for my clients and yes...it was indeed their power supply that was faulty in those instances, or in one case, the video cable the owner was using apparently had some loose connections in side it.
But I normally pre-test all consoles to verify the issues that are being reported or to find issues that the owner may not be aware of. An example of this would be a faulty player 2 difficulty switch or the paddle controllers not working properly for player 3 or player 4 on a 2600/7800 console. Because they might not normally use those functions, they aren't aware that they were faulty.

hi crossbow,
 
 nice work. agreed on the electronics. i always demanded the power supply, t.v. switch box, and controllers to boot, if a customer wanted service. many times it turned out to be a power supply problem.
 
lance
www.atarisales.com
 

hi everyone,
 
i did plug the riot eprom into my 7800 dual chip set cartridge board, and did get a reaction. bright yellow screen with background noise. so the 7800 is trying to read it, but lacks the second e-prom, i tried it in both sockets, worked better on the bottom one.
also got the atari logo on the xenophobe, but that's it. it requires the second chip also. it might be a beta version.
i found more eproms, nothing on the labels, they were so old they had fallen off. but it was dark inside the tube, so they may have survived. when i plug them in, like just about everything i ever had got out of atari, they show graphics and sound, only garbled. telling me they need more than one e-prom, and which board, and or which platform are they for?
a puzzle for sure.
lance
www.atarisales.com
 

Yep, roll with the punches it is when it comes to rain during a visit to these parks.  I went for the Food and Wine Festival in EPCOT and it started to rain and it just didn't stop.  I put on my poncho and walked around to see what I could.  Since the rain was not relenting, I decided to see if I could get into the Space Restaurant.  Sure enough, there was a short line and I was able to get in in 30 minutes.  Had a nice time in "space" and when I left, the rain had stopped.  By then, most people had left the park due to the rain, so there were no lines on the rides and I was able to still enjoy the rest of the festival.  🙂

Awww man, sorry Rick. I am glad you still had fun, I mean that's the way to be, right? Accept the circumstance and don't let it stop you! Don't let it rain on your parade....er....well you get what I'm saying 😁

We still had a lot of fun.  But the rain made it pretty exhausting after a while. 
I've been to the Florida parks when it has rained.  The difference is that in FL, it rains HEAVY for a while and then stops.  This rain was different...it was heavy and never stopped.  While we had fun still, it was sobering to think that there was flooding in the area.  Hopefully, everyone in the area and their property are all ok. 
 

I'm glad that you made it safely and enjoyed the trip.  It's so rare to have this type of rain in Southern California that it would be impossible to plan around.  I authorized my staff to tele-work through today regardless of their schedules (we've remained hybrid since COVID.)  We're definitely waterlogged after several straight days of heavy rain. 

We still had a lot of fun.  But the rain made it pretty exhausting after a while. 
I've been to the Florida parks when it has rained.  The difference is that in FL, it rains HEAVY for a while and then stops.  This rain was different...it was heavy and never stopped.  While we had fun still, it was sobering to think that there was flooding in the area.  Hopefully, everyone in the area and their property are all ok. 
 

PS - flights were good, hotel was nice.  We ate well.  Stayed healthy.  Very much to be grateful for. 

I heard about this.  Were you able to enjoy any of the park?  I went to Disneyland and California Adventure more than 10 years ago.  I had fun and enjoyed the differences between those parks and the Florida parks. 

PS - flights were good, hotel was nice.  We ate well.  Stayed healthy.  Very much to be grateful for. 

And lets not forget the awesome Trakball they made for 5200.  It feels like a real arcade controller. 

Yes... yes you do!
 

When it comes to the joysticks, I like the RetroGameBoyz all-in-one joystick.  It's a self centering digital unit that has knobs for centering the joystick and also has the keypad built-in so there is no need foy Y-adapter cables.  The UAV modification with an HDMI adapter brings it into the 21st century for modern TV sets and it's picture quality is only something we could dream about back in the day.  Now of course if you are going to go to that expense, you NEED the Atarimax cartridge to finish the setup.  

I don’t have Rescue on Fractalus yet.  I need to remedy that.

And lets not forget the awesome Trakball they made for 5200.  It feels like a real arcade controller. 

There are several controller options available today, so the non-centering CX52s are no longer an issue. Btw, the 5200 port of Defender is excellent and plays extremely well with the CX52s. (I have four of the Best Electronics upgraded CX52s and they continue to work as new after several years of use).
As others have stated, you can go the Wico controller and pad route or connect a Masterplay or MP Clone type adapter for use with any number of DB9 connector controllers. 
 
My top five original games:
Defender
Gremlins
Missile Command (Trak-Ball)
Rescue on Fractalus!
Space Dungeon (Console exclusive twin-stick shooter)
Note: Qix also works really well with the CX52 controller and I prefer to play Space Invaders with the trak-ball.
At this point in the life of this console, I feel that the only people making a big deal about the controllers are YouTubers looking for clicks or people that have not put an ounce of time into researching the console. 
I have a 2 port and a 4 port as well. Neither one is modded, but both have new/old stock motherboards and the RF output is really good on each console. 
 
Game on!

And lets not forget the awesome Trakball they made for 5200.  It feels like a real arcade controller. 

I have to say I am genuinely surprised and impressed at the responses I’m getting from other 5200 owners.  It has been unexpected.  For many, many years now I’ve heard others who have or had a 5200 complain about the controllers.  Even its sales showed issues with the controllers. But I never expected to hear people say they actually prefer the original controllers over anything else.  I was not expecting to hear that.
I dearly love my 5200.  Like some others I have at least 40 years experience with it.  Without internet to guide me I spent lots of time with used systems trying to repair faulty controllers not really knowing half the time what I was getting myself into or how to fix them.  I do have to thank my Mother for all those Atari finds in those garage sales and Salvation Army store visits.  She always grabbed them up.  I use to have a stock pile of replacements. When she passed the house got broke into.
And I wasn’t talking bad about the system.  On the contrary I was thinking a “what if” scenario. Like what if the games were given the ability to check what type of controller you was using? You connect an adapter and can use any Atari 2600 compatible joystick combined with the 5200 controller.  You’re given the option to use analog or digital controls. You then play the game using whatever controller you’re comfortable with.
 
 I'm not going against the standard controllers as I feel they are what make the 5200 unique. I was, instead, wonder If Atari knew they had an issue with the controllers they didn’t just make a quick fix like a controller adapter?  It would have made more business sense.
Yes!!  The Trakball controller is pretty awesome and works with a lot of 5200 games.  You should try using it with Pole Position sometime. That’s a real challenge! And unlike the Colecovision trackball it doesn’t need a separate power supply. 
 
So maybe I have been looking at the 5200 all wrong.  I was under the impression most people really disliked the system due to its controllers. 🤔 Maybe I need to do my own gold upgrade and see what happens.