Some clarifications / confirmations on the VBXE (+UAV)

[woj]

The boards arrived. So far I know that the 1.35 mm holes for the socket are spot on, there was no problem whatsoever pushing the socket through, it is not even a tight fit I'd say. The thickness of the board will be problematic, I will have to carefully choose the order of mounting all this on the Atari board not to snap it in half. For now I have to still wait for the VBXE itself, geographically the closest, takes the longest to arrive, seriously...

 

I also ordered myself a jig PCB to drill the holes for the DIN-13 socket, this, however, I got slightly wrong (the component footprint I got was clearly for a different socket than I bought). The signal pin as a group is fine, but the two mounting pins are too far away from the group. Nothing I cannot sort out by some tweaking with home tools though.

 

[woj]

OK, the most nerve wracking part of this job is done, and the computer still works. Spent a good part of the day doing this. Hot glue seems to totally suck for mounting the socket, as soon as I started soldering the supporting wire it just let go. Had to use 2 component epoxy, which I really normally avoid like plague for jobs like this, but it seems I had no choice. Will know if it did the job tomorrow when it properly solidifies. The adapter board seems to be fitting so far, will know for sure when the VBXE arrives (still hasn't). One thing is for sure, it will need to be lifted up by one extra socket, otherwise the bottom of the pin headers will not clear the PIA chip. Oh, and the drilling PCB jig for the socket, after modification, was just wonderful!

[+Stephen]

That's some very precise work - looks great!

[Beeblebrox]

Yup, congrats, very nice work so far.

 

Gluewise I swear by this stuff. Gives you time to place things and is incredibly strong. Never had an issue with din13 sockets using it. Clear too so it's not messy like epoxy.

 

https://www.amazon.co.uk/dp/B0012RGKJK/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B0012RGKJK&pd_rd_w=joP8m&content-id=amzn1.sym.8d91a06c-52c8-441e-afa4-963e53268566&pf_rd_p=8d91a06c-52c8-441e-afa4-963e53268566&pf_rd_r=NYPGWAKMKYBQQS0D3T4P&pd_rd_wg=isF4m&pd_rd_r=6987070a-b5ad-4a95-8eec-035cb13ec57f&s=kitchen&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw

 

[woj]

Completed wiring up the socket, the epoxy glue holds it nicely, but I also bent inwards against each other two pairs of unused socket pins and soldered them together for extra support. Since I use composite signal for hsync I could already test if the SCART cable and the socket works, and it does, sound is there and all! Incidentally I also made an interesting discovery. The crappy s-video picture I get on my living room TV (complained about it several times in my other thread) is not due to the crappy upscaler as I thought, but due to passing the s-video signal to SCART. On my small s-video equipped TV I now use I get the same kind of crappy picture (see photo) as I do on the living room TV if I connect the s-video signal through the SCART connector on the TV. So clearly the SCART is not entirely s-video friendly, or at least not Atari s-video friendly (though this is now produced by UAV, so should be up to common standard). Or it's the s-video to SCART adapter that I use. Nevermind, knowing all this I expect miracles once I get the VBXE hooked up on both displays!

[+-^CrossBow^-]

Not sure I mentioned it before when I posted previously, but even with my UAV I still had bad vertical bars in my s-video image although the composite output looked good and was better than the composite from the 130xe originally. When I installed the VBXE, I removed the RF modulator to make room for my mini din jack for the RGB output. 

 

And of course, the s-video output now looks great and is more in line with what I expected originally. So it seems in my case, removing the RF modulator corrected the vertical bars on the output. Had I known that, I would have removed it originally when I installed the UAV and not even bothered to keep the 4050 in circuit in the first place. 

 

In fact, given how the VBXE doesn't provide an NTSC friendly palette, had I known all of this ahead of time, I likely would not have bothered with a VBXE and just stuck to the s-video. I've been using the s-video output mostly anyway since it is now a clear picture output and has the proper NTSC colors as well. The VBXE will only be there for those programs that actually use now and possibly in the future.

 

[_The Doctor__]

the 4050 is used for more than you know evidently and is advised to stay in place.

[+-^CrossBow^-]

On 12/4/2022 at 8:55 AM, _The Doctor__ said:

the 4050 is used for more than you know evidently and is advised to stay in place.

Thank you for clarifying that. I do still have my 4050 in circuit and I guess I was just figuring its use wasn't much different than that of the 5200 side where the 4050 is really only needed to keep the RF output functioning. Another change I did make on my VBXE that I don't believe I mentioned before was that I removed the 75Ω resistors on the RGB output lines on the VBXE and jumped the pads since those resistors already exist in Sega RGB cable assemblies to get that brightness back to proper levels.

 

[woj]

Some relief, the VBXE arrived, mounted it, and all seems to work. After checking that it does I left it for now, I need rest, tomorrow I will clean up my desk, start assembling things back into the case and check some VBXE programs. Had a bit of a heart stopping moment, I though I have anticipated everything, but it turned out that the adapter board should have female header while the VBXE has the male headers, I really thought it's the other way round and did shopping for that. But I do surprise myself from time to time, turned out I have one, just one, but that was enough. The board tiny little bit touches the case, but it is OK. 

 

The picture quality is stunning compared to the stock s-video, I do however get slight jail bars, but otherwise it seems there is no "floating" noise I have on the s-video output. The cable is from CoolNovelties, I also noticed the DIN-13 plug (or socket) is very sensitive to touching / wobbling it, so I will have to double check my work there. (I also caught a bad solder joint I did today during the final review before powering on :D). 

 

One thing I will probably still do is to change the RGB header on the VBXE from the horizontal one to vertical, it's just too crampy next to the case edge. But I first need to check that it will clear the case on the top.

 

Otherwise now I know what the PCB thickness is for the stock VBXE adapter board, it is 1mm

 

Pictures for review

[Beeblebrox]

@woj nice work.

Are the adapter board files something you may release into the public domain as I am possibly interested.

 

Yup, the din13 and Cool novelties cable are a great combo. 

 

 

 

 

 

 

[woj]

Releasing the files is not a problem, not that I spent so much time on the design. But I am thinking now looking at the pictures - the VBXE board can be easily moved downwards a few mm, it would get rid of any remaining case clearance issues including the RGB connector. New PCB order will be just a few bucks, so I may just as well try that.

[_The Doctor__]

can it when inserting certain cartridges?

[woj]

At least my SIDE3 cart is not a problem. Anyhow, I put everything back together again, checked clearances and measured. As it turns out, I do not have much wiggle room, not if I keep the complete header where the U1MB is connected, it clears the keyboard by a thin hair. With the header removed / reduced I could move VBXE downwards 3mm and leftwards as far as it goes (as far as the adapter board layout allows to still connect the traces). That could be a good option, because then I could possibly free the space for Pokey upgrades. Otherwise, if I decide to keep the current layout (which for now I do), I could possibly move VBXE half a mm to the right to center in better in between the case parts. Either way, I made the RGB headers vertical just to avoid any leaning on the case. 

 

I played with the TV settings, and after that the picture is absolutely sweet. Also, my living room TV that I complained so much about is now doing the right thing too , picture attached.

[Peri Noid]

What if you solder the header underside the board? It makes no difference from the usage point of view but gives you some space.

[woj]

Indeed, why haven't I thought of that!

[Mathy]

Hello guys

 

You can only do that if you only have one row of pins.  With more rows, the top row will become the bottom row.  If you keep that in mind, no problem.  But forget it...

 

Sincerely

 

Mathy

 

Edited December 10, 2022 by Mathy

[woj]

Indeed, and I have not thought of that, just resoldered it. But I only use one pin there, so no problem.

[woj]

Spent a better part of today doing this, it turns out (no surprise here I guess) that if you want to squeeze out the PCB space you have to route it manually, I was nowhere near this compact with auto-router. This way it should be possible to do Pokey upgrades too  

[woj]

New revision of the board just arrived, also now in the spot on thickness and the color I wanted, some soldering to do again  Once verified to fit, this one I can easily share.

Edited January 5, 2023 by woj

[woj]

It works and is spot on. Well, OK, the perfectionist in me thinks that I could move the VBXE position back by the margin visible on the pictures, this would clear the GTIA tower a bit more and in effect, probably, I could push the whole contraption down by the extra socket that it has in between the adapter and the motherboard socket. But, it all fits nicely, the smaller board added a lot of sturdiness, the VBXE does not wobble anymore, it's good. I attach the Gerber files for this here, the thickness I now ordered is 1mm and it is perfectly fine (the previous board was 0.8mm, a bit too thin for my taste). 

 

Next on the todo list is soldering back the angled header for the RGB connector on the VBXE now that there is space, and also, against my better judgment, finishing socketing the 40 pin chips on this one (I have PIA, Pokey, and Freddie left, Pokey has to be done anyhow for the future mod), I just did that for my 800XL and now am confident that I can do it continuously without breaking anything. 

Gerber_PCB VBXE board ver 1.1 Small_2022-12-21.zip

[Beeblebrox]

@woj  nice job.

[woj]

Uff, had some close calls today with socketing the three chips. Pokey went fine, when desoldering PIA I slightly lifted one pad (my fault, got a bit too confident and rushed things ;)), but it was savable. With Freddie I did not do anything wrong, learned my lesson with PIA, but the bottom pad on pin 20 detached itself just from the heat. On top it is connected to the large ground plane, so that was also no harm done. In any case, my 130XE is now effectively fully socketed.

 

Since my next mod is stereo Pokey board (going the hard way of assembling it myself) and having the computer apart I used the chance to make all the connections for the stereo board, made a cable hooking up A4, GTIA bell, and U1MB M0, as well as the two separate audio channels to the DIN-13 socket. Effectively, once I get the Pokey board assembled, it will be all plug and play from this point on  

[+-^CrossBow^-]

@woj How are you going about building the stereo upgrade board? I'd like to do the same as I have a spare pokey now and already have a 9-pin mini din installed into my 130xe from my VBXE setup. I currently have all audio routed to all audio but can separate that out as needed.

 

 

[woj]

I am gathering parts to build @mytek's board, probably minus the PIC, as PS/2 stuff is not my thing, not yet at least 😉

[woj]

So, the stereo board is built, and it works! For the first time ever with this computer something worked on the very first attempt. I now really think that the culprit to my soldering is to clean the remains of the flux properly. Having a white PCB helps with this a lot as all gunk is very visible. Kudos to @mytek for the design, thanks!!!

 

I actually went totally overboard, since I do not need (and I can't get the parts) the PS/2 functionality, but I do want the LED on the board sitting nicely and two audio outputs (one for the DIN-13, and one for a mini jack connection to have the stereo sound also with the stock video output, without build a cable spiderweb) I made a redux clone of this board in EasyEda with all these mods in, plus I used full size resistors for everything, not RNs, since without the PIC there is more space on the board. I still need to check several things in the PCB design and my favorite factory is working at half pace during their holiday in China and not producing white boards, so it will be a while before I try it.

 

Yoomp for whatever reason (I read about it on PL forums) is reporting stereo not detected (so is my MiSTer FPGA setup), but stereo sound there works just fine. I wonder if I have some weird / older version of the game that has the detection bug that I read about, I have to check that...

 

BUT! The question of the day is: what is the red LED on the VBXE announcing?! I tried finding this information out, but I only know that folks get it when something is horribly wrong with the board. Mine is working just fine, but I do get the red LED going on and off when I run the LAMERS Old School demo. The led is in line with what's going on the screen, so to me it seems like it is signalling the blitter being active or something. More of a question than if there is something wrong with my installation is this one: WHY IS THIS NOT DOCUMENTED IN THE VBXE MANUAL!?

 

Pictures for reference