Why doesn't the CX55 VCS cartridge adaptor work with 5200 video upgrades?

[+x=usr(1536)]

@-^CrossBow^-: I'm wondering if it's possible for the 5200 video circuit to backfeed into the CX55's video path.  Conceivably, that could make it possible to have both 5200 and CX55 video but not necessarily CX55 audio if the audio is still being taken from the 5200 side.  Never tried this myself so have no idea as to the feasibility, however.

 

I'll re-check the circuit diagrams later, but it might explain a couple of things.  Of course, it still wouldn't allow a UAV or other upgrade that relies on the 5200's Luma / Sync / Colour signals for video generation to work with the CX55, though picking off just composite and audio might. 

[AtariHobbyLover]

So I got the CX-55 (VCS cartridge Adapter) to work with the UAV board by the Brewing Academy. The problem all along was the jumpers on the UAV are different for the CX-55 then ALL other mods for the UAV. Go to the bottom of the following Link.

 

https://forums.atariage.com/topic/344738-4-port-upgrades/

 

 

[+-^CrossBow^-]

1 hour ago, AtariHobbyLover said:

So I got the CX-55 (VCS cartridge Adapter) to work with the UAV board by the Brewing Academy. The problem all along was the jumpers on the UAV are different for the CX-55 then ALL other mods for the UAV. Go to the bottom of the following Link.

 

https://forums.atariage.com/topic/344738-4-port-upgrades/

 

 

Very cool! But how are you routing the video and audio from the VCS adapter? Or are you using the VCS adapter by itself as its own device? Because the issue of getting a UAV inside the vcs adapter is awesome, but the real goal of this post I believe, was to find a way to get a UAV working for both the VCS adapter and the 5200 with the 5200 still providing the power etc. So basically how to get the video from the VCS adapter mixed with the 5200's UAV essentially. The main issue is the lack of empty pins on the cartridge port to accomplish this.

[+x=usr(1536)]

1 hour ago, AtariHobbyLover said:

So I got the CX-55 (VCS cartridge Adapter) to work with the UAV board by the Brewing Academy. The problem all along was the jumpers on the UAV are different for the CX-55 then ALL other mods for the UAV. Go to the bottom of the following Link.

 

https://forums.atariage.com/topic/344738-4-port-upgrades/

Nicely done!  This kept getting pushed down my to-do list by various other things over the past couple of years; good job on figuring out the jumper block settings.

36 minutes ago, -^CrossBow^- said:

Very cool! But how are you routing the video and audio from the VCS adapter? Or are you using the VCS adapter by itself as its own device?

If I'm understanding the post correctly, he's routing audio and UAV video from the CX55 to dedicated outputs.  The 5200 is just a power supply for it at that point.

36 minutes ago, -^CrossBow^- said:

Because the issue of getting a UAV inside the vcs adapter is awesome, but the real goal of this post I believe, was to find a way to get a UAV working for both the VCS adapter and the 5200 with the 5200 still providing the power etc. So basically how to get the video from the VCS adapter mixed with the 5200's UAV essentially. The main issue is the lack of empty pins on the cartridge port to accomplish this.

It's a good accomplishment, to be sure, but this is correct as far as the intent of that thread goes.

[AtariHobbyLover]

I plan on using the Bobby box connected to the CX-55 because I am only interested in S-Video. You can use the UAV composite and go thru pin 24 to the 5200. Maybe use a 1n914 diode to your composite RCA jack from the 5200 if you get interference.  But I am not aware of another free pin. However, there is more than one ground pin on J1. You could try to isolate a ground pin one at a time and test each of your 5200 cartridges and the VCS adapter. You might get lucky. Or mount a RCA socket for audio into the CX-55.

[AtariHobbyLover]

Another interesting thing I just found was, if you have a 4 port 5200 that does not support the VCS adapter, all you have to do is 1 thing to get the CX-55 to work with the UAV in the CX-55.  Just supply the CX-55 with power. Run a wire from Pin 12 of J1 on the 5200 to (adapter in) bottom leg of L8.

 

 

[+x=usr(1536)]

10 hours ago, AtariHobbyLover said:

I plan on using the Bobby box connected to the CX-55 because I am only interested in S-Video.

Makes sense.  I've been looking at how to bring all the signals over to the 5200 so that its UAV can handle the video end of things for both composite and S-Video.  Either way works 

10 hours ago, AtariHobbyLover said:

But I am not aware of another free pin. However, there is more than one ground pin on J1. You could try to isolate a ground pin one at a time and test each of your 5200 cartridges and the VCS adapter.

Yup, this was one of the approaches that was being considered.  In terms of modification to both the CX55 and 5200, though, it's generally been thought of as more work (with potential for damage to either unit during modification) than it's worth for the end result.

[AtariHobbyLover]

I have two 4 port units that did not work with the VCS adapter and both had to be moded. Both units were not identical with each other. The easy one had pin 24 already isolated to a solder point I could tap off of. The other one had pin 22,23,24 to ground. I had to unsolder J1 then use a dremel to isolate pin 24. But for some people, they really don't care about the RF output, but want the CX-55 to work with great audio and video. This easy 1 step mod to add power to pin 12 will make it a lot easier. I prefer keeping the RF intact as original.

[0078265317]

I am lucky I found an asterisk that works out of the box with the vcs adapter.

[RockLobster]

On 5/1/2023 at 11:54 PM, x=usr(1536) said:

Bear in mind that when the adapter is connected to the 5200, the 5200 does nothing more than provide power to the adapter and output for its audio and video signals. 

Seems like the same design as the 2600 "adapters" for the ColecoVision and Intellivision.

[+-^CrossBow^-]

2 hours ago, RockLobster said:

Seems like the same design as the 2600 "adapters" for the ColecoVision and Intellivision.

Exactly the same...

 

Difference is that Coleco foresaw this ahead of time and so the console was designed with extra power provided off the expansion port and lines for video and audio to come into the console. Whereas with the 5200 and Intellivision, their initial models didn't account for this. So the modifications for those older consoles is to essentially use extra ground pins off the cartridge ports to re-purpose for the required power, audio/video needed and route it back through to the RF modulators.

 

One thing I can't figure out is why Atari felt the need to deliver the raw input DC off the port straight to the VCS adapter? It would have been easier for them and safer if they had just routed +5 straight to the VCS adapter that was only switched on when the power button was pressed. Instead, you have raw +12v active on the cartridge port as soon as you plug in the DC power cord into the console. The hardware in the 5200 could handle the current draw as would the 5200's PSU? It would also mean that power regulation wasn't required inside the VCS adapter since you are already supplying a steady +5 to it further cutting a little bit of cost and space inside the adapter?

 

Unless there is something I'm missing on the way it all works?

 

[RockLobster]

1 hour ago, -^CrossBow^- said:

Unless there is something I'm missing on the way it all works?

Maybe they anticipated having a device that needed to be powered up / initialized prior to the 5200 for some type of handshaking?

[+x=usr(1536)]

25 minutes ago, RockLobster said:

Maybe they anticipated having a device that needed to be powered up / initialized prior to the 5200 for some type of handshaking?

Possibly, but it doesn't seem like there'd be a ton of time between inserting that device and hitting the power button on the console.  Granted, even a split second is a lot when talking execution time, but it seems more like a weird design decision than anything else.

 

One scenario I can envisage with this is allowing devices with power requirements different to the 5200's (e.g., 6V, 9V, 12V, etc.) to be powered from the console directly and not require an external PSU - just install the appropriate voltage regulator in the device and go to town.  Additionally, given Atari's design of the antenna switchboxes on the 4-port systems being a single-cable solution, this would be in keeping with that philosophy.

 

Still though, I don't get it either 

[AtariHobbyLover]

The 5200 has two 7805 regulators on massive heat sinks. Perhaps the CX-55 drew two much current for either of them to work within specs. Another reason might be for noise in either the sound or picture since the 5200 is running at the same time as the CX-55. What's interesting is the CX-55 had two power supply designs. The first had a variable pot and transistor. The last design had a 7805.

 

BTW. I made a breakthrough in finding pins on J1 that will allow me to pass the UAV output and audio from the CX-55 to the 5200 without using a BoBby or RCA connectors on the CX-55. I should have that info ready later today or tomorrow.

 

 

[+-^CrossBow^-]

5 minutes ago, AtariHobbyLover said:

The 5200 has two 7805 regulators on massive heat sinks. Perhaps the CX-55 drew two much current for either of them to work within specs. Another reason might be for noise in either the sound or picture since the 5200 is running at the same time as the CX-55. What's interesting is the CX-55 had two power supply designs. The first had a variable pot and transistor. The last design had a 7805.

 

BTW. I made a breakthrough in finding pins on J1 that will allow me to pass the UAV output and audio from the CX-55 to the 5200 without using a BoBby or RCA connectors on the CX-55. I should have that info ready later today or tomorrow.

 

 

Again, I've measure this and the 5200 only pulls about 750mA from my bench PSU when running the AtariMax cart on it. So there is plenty of current across both of those 7805s to handle it. Unless they are only 500mA rated output regulators or something? But I'm guessing they are 1A output given the PSU on the 5200 can output nearly 2A on its own. I'm sure all of this was originally done because Atari planned/hoped that the expansion bus on the rear corner could be used to add additional devices and they were liking wanting to power those devices from within the console hence the overkill on the power setup in the 5200. 

 

If one of those pins on J1 is 28...then that won't work for me. I bodge a wire from that pin to the 4050 reset pin for use with one of my flashcarts that needs it for resetting back to the game menu. 

 

 

[+x=usr(1536)]

2 hours ago, AtariHobbyLover said:

BTW. I made a breakthrough in finding pins on J1 that will allow me to pass the UAV output and audio from the CX-55 to the 5200 without using a BoBby or RCA connectors on the CX-55. I should have that info ready later today or tomorrow.

 

Interesting, and definitely want to hear about it.  Does this apply to a 2-port, 4-port, or both?

[AtariHobbyLover]

Today turned into an extremely busy day for me. I have not completed my discovery or testing. I still need to go thru ALL of my 5200 carts which exceed 45. I got half done tonight at midnight.  I also have the ultimate. I am so thrilled that Mule.bin works!  So I will give you a teaser. To answer the last email:

 

[AtariHobbyLover]

Sorry. I got distracted by a family member and then went to bed. Yes, of course pin 28 is one that I found. Pin 24 for sure. I think 30 also. I need to test pin 10. Only some carts use pin 10. Pin 14 gets grounded when a cart is put in. Why cant we keep it grounded all of the time and than use that pin? Some carts use a separate ground and shield from J1, yet J1 does not have a separate shield in the 5200. 12,13,23,25 are all tied together to ground. 12 and 13 on J1 is suppose to be ground. 23,25 is suppose to be shield. It looks like I can take one from 12,13 and 1 from 23,25, But do I really need a shield inside a cart? I opened up DigDug. It had a shield. Pitfall did not.  I am currently testing with 2 different revision 4 port 5200's. I also have one 2-port which I will eventually test.

 

I also did a test taking all of the output lines from the UAV in the CX-55 and placing them on top of the same lines on the UAV in the 5200 to see if it would cause any issues. It was fine. The ONLY thing I saw was the brightness very slightly dimmed when I did that vs connecting the monitor directly to the CX-55 UAV. I only noticed it on darker 2600 games like Space Invaders. Games like Dragster has so much color, there was NO noticeable difference. I also tried using a 1N914 diode in line. This blocked the video entirely. Running the 5200 games would not be affected since you effectively disconnect the CX-55 UAV.

 

Audio. My 5200 uses the 2.2k resistor and a 10uf electrolytic capacitor tied to the top of R50 in the 5200. I run a wire from the minus side of the cap to my monitor. When I take the audio from the top of R12 in the CX-55 and tie it directly to the audio lead going into the monitor, it works perfectly.

 

My goal is to bring over the UAV Composite, Luma, Chroma, and audio from the CX-55 using the pins going into J1. And possibly having maybe an extra pin available to do a reset like you are using on pin 28, or maybe the old CX-55 composite/audio being used for the RF pin 24 if you want to make the RF work also.

 

Since I was successfully able to tie the output from the CX-55 UAV and audio to the 5200 UAV and audio, all I have left to figure out what pins I can repurpose.

 

 

 

 

[+-^CrossBow^-]

1 hour ago, AtariHobbyLover said:

Sorry. I got distracted by a family member and then went to bed. Yes, of course pin 28 is one that I found. Pin 24 for sure. I think 30 also. I need to test pin 10. Only some carts use pin 10. Pin 14 gets grounded when a cart is put in. Why cant we keep it grounded all of the time and than use that pin? Some carts use a separate ground and shield from J1, yet J1 does not have a separate shield in the 5200. 12,13,23,25 are all tied together to ground. 12 and 13 on J1 is suppose to be ground. 23,25 is suppose to be shield. It looks like I can take one from 12,13 and 1 from 23,25, But do I really need a shield inside a cart? I opened up DigDug. It had a shield. Pitfall did not.  I am currently testing with 2 different revision 4 port 5200's. I also have one 2-port which I will eventually test.

 

I also did a test taking all of the output lines from the UAV in the CX-55 and placing them on top of the same lines on the UAV in the 5200 to see if it would cause any issues. It was fine. The ONLY thing I saw was the brightness very slightly dimmed when I did that vs connecting the monitor directly to the CX-55 UAV. I only noticed it on darker 2600 games like Space Invaders. Games like Dragster has so much color, there was NO noticeable difference. I also tried using a 1N914 diode in line. This blocked the video entirely. Running the 5200 games would not be affected since you effectively disconnect the CX-55 UAV.

 

Audio. My 5200 uses the 2.2k resistor and a 10uf electrolytic capacitor tied to the top of R50 in the 5200. I run a wire from the minus side of the cap to my monitor. When I take the audio from the top of R12 in the CX-55 and tie it directly to the audio lead going into the monitor, it works perfectly.

 

My goal is to bring over the UAV Composite, Luma, Chroma, and audio from the CX-55 using the pins going into J1. And possibly having maybe an extra pin available to do a reset like you are using on pin 28, or maybe the old CX-55 composite/audio being used for the RF pin 24 if you want to make the RF work also.

 

Since I was successfully able to tie the output from the CX-55 UAV and audio to the 5200 UAV and audio, all I have left to figure out what pins I can repurpose.

 

 

 

 

Well on the 2 port you will find that some of those redundant grounds now have traces on them that lead back to the RF modulator to control the power input and video/audio outputs. The issue with using pin 28 or some of the others has to do with one particular flash cartridge device called the BackBit Pro. It has the ability to do a reset back to menu without power cycling the console but uses and expects pins on the cartridge port to be a certain wait to take advantage of this feature since an actual system reset doesn't exist from the cartridge port itself. The BBPro adapter has a selector switch to choose between a 2 port console or 4 port. The switch in 4 port mode only works on 4 port units that have been modified to use the CX-55 adapter, or if you attach a bodge wire from pin 28 back to the reset on the 4050 as I did and then bridge a jumper pad on the BBpro adapter to specify this.

 

So obviously what is being done is essentially a special case one off project for your needs. But for main stream use publicly it might not be completely feasible to do all of this. And it still requires having to install a second UAV in the mix. What would be more awesome would be if all of the pins that were needed could be disconnected with a switch / circuit allowing you to just run the TIA signals directly out through the cartridge port and then route it to a single UAV setup to handle both systems. But that is a more complex solution to be sure.

 

[+x=usr(1536)]

2 hours ago, AtariHobbyLover said:

Since I was successfully able to tie the output from the CX-55 UAV and audio to the 5200 UAV and audio, all I have left to figure out what pins I can repurpose.

Which is definitely an approach that could be taken (and has, to some extent, been considered previously).  I applaud your work, but find myself in agreement with @-^CrossBow^- that this is something that would be better-suited to a one-off build rather than for mass adoption.

14 minutes ago, -^CrossBow^- said:

What would be more awesome would be if all of the pins that were needed could be disconnected with a switch / circuit allowing you to just run the TIA signals directly out through the cartridge port and then route it to a single UAV setup to handle both systems. But that is a more complex solution to be sure.

This was exactly what drove me to lean towards the interconnect idea: the lack of suitable pins on the cartridge port just brought up too many compromises with the potential for bringing about compatibility (or damage) issues if they were repurposed.  Granted, either approach carries risks, but keeping them to a minimum is appealing.

[AtariHobbyLover]

Understood. Can the 2-port unit be modified to remove those redundant now used ground pins? If its only used for the RF, who cares? I'll let you know what I come up with on my 4-port. It probably won't get done today.  I specifically wanted a 4-port to play 4 player MULE. Also curious, what does the BBPro do that the Ultimate can't? The Ultimate has a reset on the top of the cart.

[+-^CrossBow^-]

8 minutes ago, AtariHobbyLover said:

Understood. Can the 2-port unit be modified to remove those redundant now used ground pins? If its only used for the RF, who cares? I'll let you know what I come up with on my 4-port. It probably won't get done today.  I specifically wanted a 4-port to play 4 player MULE. Also curious, what does the BBPro do that the Ultimate can't? The Ultimate has a reset on the top of the cart.

It does?! My Atarimax Ultimate doesn't although there is a spot on the board I think for a reset switch that wasn't populated. But I think when I looked at in detail it didn't seem to go to anything. So do the newer AtariMax carts have a reset back to menu button then? Because again, the one I own requires me to power cycle the console each time I want to change games.

 

Mine is also housed in a 5200 cartridge case that I assume is from a donor Pac-Man or something.

 

Aside from that the BBPro doesn't have anything additional over the Atarimax and in isn't as feature rich. But, then again the BBPro is designed to work with many many different consoles and computers.

 

 

[AtariHobbyLover]

The Ultimate case is brand new. Definitely not from an old Cart. Here is a picture of the reset button. Also does anyone know what that protruding clear bubble is between the T and the A?

[+x=usr(1536)]

2 hours ago, AtariHobbyLover said:

If its only used for the RF, who cares?

The daily-driver 2-port that I have now came to me in a non-working condition.  The RF modulator had been removed, and it appeared as though someone had, at one time, started but not finished a composite mod on it.  The first job was getting an RF modulator installed so that it could be further worked on with at least baseline video available.

 

FWIW, almost every UAV installation I've done has been carried out with the express goal of keeping RF intact largely to allow for a lowest-common-denominator video output in the event of troubleshooting requiring it.

1 hour ago, -^CrossBow^- said:

My Atarimax Ultimate doesn't although there is a spot on the board I think for a reset switch that wasn't populated.

Ditto; I also have to power-cycle the console to change games.  Maybe newer units have the switch?

37 minutes ago, AtariHobbyLover said:

Also does anyone know what that protruding clear bubble is between the T and the A?

It's a file activity LED and should blink on SD card accesses - at least, that's how mine works.

[+x=usr(1536)]

Double post.