Some clarifications / confirmations on the VBXE (+UAV)

[+-^CrossBow^-]

I just installed my VBXE last night into my 130xe and also have a UAV in place. What I had to do in order to get the clearance needed so that the VBXE wasn't touching the UAV, was to remove the sockets I had in place on the UAV. Soldered the 4050 directl to the UAV pins that used to go into the socket, and then soldered that entire assembly to the main board. So... no sockets in the mix at all. This isn't too different from what I've had to do on some 5200 UAV installs to ensure that the UAV wouldn't walk out of the socket in shipping. 

 

I don't own an ST nor have any of the cables that use the 13pin din connector, so I removed the RF modulator on my 130xe and installed one of the many 9-pin mini dins I have on hand and wired it up using Sega RGB pinouts. 

 

I took csync directly from pin 15 of the 4050 by just soldering a wire to the top of the UAV pin that is directly attached to pin 15. I also attached the needed +5v to the 9-pin using he +5 via that used to power the RF modulator. Didn't even check to see if composite is still working but I imagine it would since I'm using the UAVs composite output directly to the original monitor output port. I only tested to make sure that s-video and RGB from the 9-pin was working through the VBXE. Only issues I've seen is that many of the VBXE demos either require a PAL 8-bit and tell me as much, or will run with some graphic glitching here and there. The VBXE Commando that was released elsewhere in the threads also works, but only the ATR version of it through my Funinet as the xex version will just eventually hang on the commando loader screen.

 

So what you might just have to do in this case, is get or use a low profile socket, solder the GTIA directly to your fixer board and then insert all of that into the lower profile socket on the mainboard. Doing that, I think you can get it to clear at that point while still being able to replace that GTIA in the future.

 

Here is how that setup looks on my 130xe. I'm not wild about how much slack there still is on the VBXE board as it just wants to fall forward since there isn't any support on that front edge of it. That is the reason I still didn't try using at least 1 socket on the UAV setup was because the front edge of the VBXE would still possibly touch the UAV.

 

 

Here is my initial test using a 9-pin Sega RGB cable to my Tink2x SCART shown on the right on the LCD, and the UAV providing the s-video on the left PVM crt.

 

 

 

[woj]

Thanks! First, so envious of the PVM, had a chance last year to buy one in very good condition, only that I did not have enough money stashed up (my rule of operation is that my hobbies have to mutually finance themselves, this one is the one not bringing any profits whatsoever 😉).

 

Right, so I did not even think UAV clearance would be an issue, now I see it is and in retrospect it should have been obvious. So thanks a lot for bringing this to my attention!

 

Adding all this up it starts sounding like a custom designed adapter board for VBXE that would orient the VBXE the same way as on XL / upwards, but shorter so that the side of it would fit before the CPU and would not have to be raised a lot (the adapter itself I mean) to go over the CPU that also has an adapter. And so that VBXE connection pins would still fit before they hit the case and I would not need yo solder the wires directly to VBXE.

 

Last night I also examined the inside of the computer to see where I could relocate VBXE using a flat cable, but so far have not found a good place. Knowing the exact dimensions of VBXE would help here 😉 😉 😉

 

EDIT: I also noticed you have your UAV connected to the stock video output socket through ferrites, does it help anything more with the picture quality? The UAV manual suggested not to do so, so I hooked them up skipping the ferrites.

Edited November 10, 2022 by woj

[+-^CrossBow^-]

1 hour ago, woj said:

Thanks! First, so envious of the PVM, had a chance last year to buy one in very good condition, only that I did not have enough money stashed up (my rule of operation is that my hobbies have to mutually finance themselves, this one is the one not bringing any profits whatsoever 😉).

 

EDIT: I also noticed you have your UAV connected to the stock video output socket through ferrites, does it help anything more with the picture quality? The UAV manual suggested not to do so, so I hooked them up skipping the ferrites.

The PVM I happened to find locally. We have a radio and electronics enthusiasts hobby shop here where I can get quite a few components etc. But they also have older tech brought in to be gotten rid of and they will sometimes test it out, fix it if it is simple and then sell it back out for cheap. That PVM is only like 8 or 9 inch screen and it can ONLY do composite and s-video through BNC connectors on the back. So it is mainly used for just composite and s-video stuff. Although that LCD monitor is older and actually has both composite and s-video inputs too. But I find the picture quality looks best on the PVM using those outputs. 

 

As for how I connected the UAV. I do not think the ferrites really make any difference either way. They are designed to filter unwanted stuff out so I figured it was best to attach the UAV outputs through the ferrites before the monitor out port vs bypassing them. The composite output looks great (For composite anyway) on this 130xe but the s-video still had some thin vertical jail bars on the screen even with my Hercules s-video cable I use on it. Now that I've removed the RF modulator it might have cleared some of that up but I've not put it all the main game room yet to test. I do expect the RGB output to be a little darker downstairs given I'm using Sega RGB cables that have additional resistors and caps in the SCART housing. But given what I see on the upstairs setup, it isn't likely to be any issue in this case. But I probably should have installed one of the 8-pin mini dins instead and used that cable setup. But pretty much everything I have in the game room on RGB is setup for using Sega cables.

 

[woj]

I am getting somewhere with this, starts to be a very cool project, first time I am designing a PCB, not the last time, that I am now so very sure of  The measurements are not yet verified (no access to the Atari), but I am quite sure I can make it work this way. I also now figured out that I should not buy the XL version, as far as I understand the adapter board is soldered in there for good, while the XE version has a connector. Regardless of going forward with the VBXE itself or not, this adapter board will happen, and so will prepping the Atari, I mean socketing the ANTIC.

[woj]

CAD - Cardboard Aided Design  It's converging, it is still overlapping by less than 1mm with the CPU adapter. One option is to just lift it with one extra socket (it will probably need that anyhow for the VBXE to clear the case around the cartridge area), but could then still touch things here and there with unclear consequences. The other one is that I will try to make it narrower on the CPU side by 1mm and see if the traces can still be routed (I use autorouter here, there is no way I can solve this routing puzzle by myself). As far as I can say, it does not stand in the way of any prospective Pokey mods, but I have to recheck that (PokeyMax would be fine for sure, not entirely certain about mytek's stereo board).

 

EDIT: As I complained in my other thread, yet again I had problems sitting the ANTIC in after taking it out for this, I really do not think precision sockets are such a great idea... For upgrades for sure, for just sitting an IC directly not so much.

Edited November 13, 2022 by woj

[Peri Noid]

2 hours ago, woj said:

Put it in the case and check again. I sense some potential problems.

Edited November 13, 2022 by Peri Noid

[woj]

2 hours ago, Peri Noid said:

Put it in the case and check again. I sense some potential problems.

I am not sure what you are getting at, I suspect that you mean it will have to be lifted quite high to clear the cartridge slot casing part. Yes, that I know, the VBXE is 3 "units" wider than the connector on each side and it won't fit before that part of the case. But as far as I could measure, one extra socket will do it, if not I can try tall headers instead, or both. What can become a concern is fitting under the top cover.

[Peri Noid]

Oh, nevermind. It seems I had a different memories of the insides. And they were not precise enough :-) Which is actually good since your project is ... good :-)

[woj]

With providing clearance for the CPU I had to extend the board to the right, it will now overshadow the PIA a bit, but that's not a problem. Will print tomorrow and check again. 

[Peri Noid]

If you're planning to install stereo, you may consider Pokey (and neighbourhood) clearance as well.

[woj]

56 minutes ago, Peri Noid said:

If you're planning to install stereo, you may consider Pokey (and neighbourhood) clearance as well.

Yes, I was thinking about that. PokeyMAX would fit, and that's the thing I'd actually like to get, eventually (unavailability due to the same reason as for Sophia 2 I guess). Neither Lotharek's simple stereo nor mytek's TK-II stereo board would fit, just checked, but then I work on the assumption that if I have a dead Atari to source the second Pokey from, then I'd also have a good GTIA and then I could use the "factory" adapter board for VBXE. My other Atari is very much alive and I am not touching it for sure, certainly not cannibalizing it for a Pokey  So for my current situation it should work. Just need to re-verify the current dimensions (forgot to say that I also extended it a tiny bit on the top to enable routing), figure out the PCB thickness to have the precision socket sticking out just enough on the bottom (for the CPU adapter I ordered the standard 1.6mm and that is a bit too thick, though working, perhaps one of you know the sweet spot for this?), and I can do a test batch of this small board. 

[woj]

Updated cardboard version test fitted. As such it is fine, it is, however, going to be a tight fit game anyhow. There is already one extra socket underneath (without it it may not clear the cartridge port pins, difficult to say with soft cardboard), but it still probably won't clear the "notch" on the case (the thing between the cartridge port and the ECI) without lifting up a bit more (longer headers should be sufficient, or one more socket). The other option is to file the case a tiny bit (it won't be a lot by the looks of it). Even with this, the pin VBXE headers going towards the case will make the connector very close to the case wall (but fitting). One other option, now that the whole thing had to be lifted up anyhow, is to move the whole VBXE downwards (=redesign the adapter board), but then the headers on the other side of it might have problems clearing the keyboard. All those questions cannot be answered until I have the actual VBXE hardware in my hands (or an accurate model, too lazy to do that though). 

 

The next task to solve is the video connector on the back. One option (very likely) is @flashjazzcat's way of DIN-13 connector, but then I was also thinking, I own a MiSTer, so if I'd go a VGA connector way I could make a cable that would work both for the Atari and the MiSTer, or so I believe. But that would require a separate judio hack and much more nasty case cutting / modding, really not sure I am up for it... Especially now that I have seen Jon's video on the SF551 drive  I think it is wise to go tried routes rather than to find new ways and hitting walls.

 

A question at the end: anyone know a good source for the DIN-13 PCB connector in mainland Europe? All I find is China with ~1month waiting times. I know Mouser probably would have it, the postage is a killer though, would have to buy a whole bunch of other things at the same time to make it worth the postage costs.

 

EDIT: Looking at the pictures again - it just hit me, if I sink in this sticking out transistor I have much more space to play with, I do need to build the VBXE model, because it just may fit nicely in the cartridge slot space in between the casing.

Edited November 15, 2022 by woj

[flashjazzcat]

46 minutes ago, woj said:

A question at the end: anyone know a good source for the DIN-13 PCB connector in mainland Europe? All I find is China with ~1month waiting times.

I ordered ten connectors from China on eBay (I was not prepared to pay ~GBP 5 for one connector) and they arrived in less than two weeks.

[Beeblebrox]

I get mine in the UK from here. Very affordable. I've bought several over the last month or so.

 

https://www.ebay.co.uk/itm/293211239741

 

[flashjazzcat]

Not bad at all if you buy in bulk. Nice one.

[woj]

Would one of you be so kind and give me precise measurements of the VBXE in mm? My best approximation so far is 66mm by 48mm and the distance from the header edge to the board edge 1mm (on the long side, that's what matters). But it can as well be 49mm instead of 48 and that makes a huge difference to me. Some early post by Candle on VBXE suggest 66 by 44, but that's definitely not true. 

[Peri Noid]

See yourself. 

[woj]

20 minutes ago, Peri Noid said:

See yourself. 

Perfect, thanks! 

[woj]

I think the design converged. The transistor will be "neutralised". With a little bit of luck it all will be able to sit low enough to use vertical headers on the sides of VBXE, especially the side near the case edge. 

 

The only real question now is how thick should the board be for the precision socket to stick nicely out on the bottom of the adapter. Measurements tell me 1.2mm (this is how much space there is between two stacked precision socket plastics). But then I'd need some reserve space for soldering the socket pins on the bottom, the experience with the CPU adapter tells me the socket cannot be just pressed into the holes, even though they are sized for the socket to snap in, sometimes the contact is poor. So I am hesitating if that should not be 1mm (this, one the other hand, is a bit thin for a board of such size and shape that will be inevitably bent during installation etc.). Any opinions?

[+Stephen]

3 hours ago, woj said:

The only real question now is how thick should the board be for the precision socket to stick nicely out on the bottom of the adapter.

I can only answer based on a recent design @mytek did - for his UVG boards, 0.8mm was specified (which I believe is 50% thickness of normal).  I took a ton of photos of the ones I assembled, and oddly do not yet have a single pic of the bottom.  You can check his design here https://ataribits.weebly.com/ugv.html

 

[+mytek]

2 hours ago, Stephen said:

I can only answer based on a recent design @mytek did - for his UVG boards, 0.8mm was specified (which I believe is 50% thickness of normal).  I took a ton of photos of the ones I assembled, and oddly do not yet have a single pic of the bottom.  You can check his design here https://ataribits.weebly.com/ugv.html

Yep 0.8mm thick PCB material and 0.056" (1.4-1.45mm) diameter holes is what I always use. If you are specifying the hole diameter in mm you should first verify what the plating thickness is and then based on that select the minimum size drill required that will still allow the shoulder of the machine pin to pass through. Even though this will be soldered, it's best to be close to a press fit.

 

Example

[woj]

I figured out the hole diameter for my sockets to be 1.35mm based on the socket itself but also the design of the CPU adapter board, so that's what I will go for. Many thanks for the hints on the PCB thickness, I'd never consider to go as low as 0.8mm, I thought 1mm is pushing it already... 

 

Edited November 18, 2022 by woj

[+mytek]

9 hours ago, woj said:

I figured out the hole diameter for my sockets to be 1.35mm based on the socket itself but also the design of the CPU adapter board, so that's what I will go for. Many thanks for the hints on the PCB thickness, I'd never consider to go as low as 0.8mm, I thought 1mm is pushing it already...

1.35mm might not allow any tolerance for a slight accumulative error over the distance of 20 pins and/or the thickness of the plated through holes. Or in other words if everything isn't absolutely perfect, you might struggle to press the socket into the board. I went with the 0.056 Inch diameter specification (1.4224mm) which works perfect considering that the manufacture probably bumped it to the closest mm drill size (likely 1.4mm).

 

My board designs are always based upon a thousandth of an inch precision (mils) just out of old habit that I picked up many years ago when I first got into the PCB layout game. Back then most all of the components I was using were also based upon this scale. Although now days it's best to use a mm standard

[woj]

43 minutes ago, mytek said:

1.35mm might not allow any tolerance for a slight accumulative error over the distance of 20 pins and/or the thickness of the plated through holes. Or in other words if everything isn't absolutely perfect, you might struggle to press the socket into the board. I went with the 0.056 Inch diameter specification (1.4224mm) which works perfect considering that the manufacture probably bumped it to the closest mm drill size (likely 1.4mm).

I can't and shouldn't argue with this, I am, however taking my chances. The Sally adapter board design that I got from the Internet and already implemented works perfect in this respect, and I verified those holes to be 1.35mm (the Gerber file says so). In any case, the board was ordered today (wanted white, but the color in combination with small thickness was too expensive, so it will be green 😞) along with another cool PCB thing I came up with, but I will reveal only once I know it works 😉. If all toys arrive before December with a reasonable margin it will all be known by then, otherwise from the 1st of December I switch my past time mind to Advent of Code, which may mean coming back to this in January 😀.

[+mytek]

36 minutes ago, woj said:

I can't and shouldn't argue with this, I am, however taking my chances. The Sally adapter board design that I got from the Internet and already implemented works perfect in this respect, and I verified those holes to be 1.35mm (the Gerber file says so).

Well just for grins I pulled out the digital calipers and checked one of my machined pin sockets...

 

 

The reading kept flipping between 1.36 and 1.37, so putting it at 1.365mm for the diameter of the pin shoulder.

 

Checking my Gerbers for the UGV project...

 

And for reference, here's a good article that talks about proper sizing of holes for PCBs: PCB Hole Size Tolerance  (take note of the fact that not all components are sized exactly the same from different vendors, so some extra tolerance should be added to take this into consideration).

 

Not much more that I can add besides you need to do what you feel is right and hope that it matches your previous experience