Some clarifications / confirmations on the VBXE (+UAV)

[woj]

I did study a bit what VBXE could bring in for me and how it is installed, I am mostly after still improving the picture quality (right now having UAV), but also after 80 columns (though quite sure it wouldn't work with MAC/65 for example?) and be able to try the handful of VBXE games. All in all, I am not convinced to be honest, but please just quickly tell me if I got this right:

 

- VBXE replaces GTIA, but only if I use the RGB output of the VBXE, otherwise the stock video output goes from the onboard GTIA that is still doing its thing (and none of the extra video features are available there)?

- The stock GTIA cannot be removed, even if the stock video output is not used? (I am sensing I am getting this one wrong)?

- It will work fine (putting aside any clearance issues) with UAV, and I can take the CSYNC signal from the composite output of the UAV instead of 4050 without loss of picture quality?

- I cannot take the pre 4050 CSYNC signal directly from GTIA for the video connector?

- There is no way on Earth VBXE will clear my GTIA fixer board (see photo) without building a tower of sockets under the ANTIC VBXE adapter board? And perhaps then not even clearing the case cover?

 

 

[Beeblebrox]

@woj  My pennies worth.

 

Correct. The (GTIA) ANTIC chip still sits on the VBXE board and is used as part of the upgrade. The VBXE replaces the crystal and provides the clock and then all the extra features.

 

I've not done a VBXE install on an XE yet. With the 800XL VBXE install I undertook, (I followed FJCs 800XL DIN13 and VBXE install vids - see here) it can use the DIN5 with composite and S-video out, where you can not view VBXE content from this. Or alternatively you can hook up to the installed DIN13 socket which allows you to view it all - standard video output as well as VBXE - as the VBXE's RGB output and audio is all hooked up to the DIN13. My DIN13 is wired up to use the Cool novelties 1088XEL compatible DIN13 to SCART AV cable.

 

 

Of course DIN13 socket is not a prerequisite. I just preferered it as it is discreet and minimal mods to the case are needed (the old RF case hole just gets enlarged in essence).

 

AFAIK if installing the VBXE there is no real point in installing a UAV other than for enhancing the stock output via the Din5. Then again maybe there is for some. Not sure how that works when you have a VBXE installed alongside a UAV given the components removed from the board for the VBXE install that UAV might need. Correct me if I am wrong here people.

 

I guess even if you don't really buy into the enhanced graphics modes, colours, etc of VBXE (many don't on principle which is fair enough) - as a means for nice video output and for the 80 columns, etc it is arguably worth it. 

 

Plus at present getting UAV this side of the pond - (in the UK in my case) - is not a viable option once you take into account international postage costs and import duties; and Sophia 2 is not available any time soon owing to the global chip shortage .

 

There is Candle's pending Spectre board upgrade UAV equivilant as well (Composite and S-video): 

 

 

Basic VBXE specs:

 

Device info: 

• RGB output providing crisp clear picture using LCD TV or RGB monitor

• up to 1024 colors on screen from 21 bit palette

• graphics resolution up to 640x480i (640x240p) in 64 colours, 320x240p in 1024 colours, and 160x240p in 1024

• true 80 char mode for text display

• blitter with 7 modes of operations capable of zooming displayed data, transparency, collision detection and many other features

• full downward compatible with GTIA chip

• and many, many more

Edited November 7, 2022 by Beeblebrox

[chevymad]

Uh, VBXE replaces the Antic chip.  It will work fine with a UAV installed, though I've not done that in a regular Atari computer, I just have had both in my XEL and XLD. 

[Beeblebrox]

12 minutes ago, chevymad said:

Uh, VBXE replaces the Antic chip.  It will work fine with a UAV installed, though I've not done that in a regular Atari computer, I just have had both in my XEL and XLD. 

Doh, you are right! I meant ANTIC. I'll update my post. 

[Mathy]

Hello guys

 

Here's an alternative to the 13 pin connector:

 

Somebody is working on SAVO.  A small PCB that does nothing else but provide you with a way to use the Sega Saturn 10 pin connector on the 8 bit Atari.  The PCB takes up the space the RF modulator usually takes.  The connector can be accessed via the hole that was used by the connector on the RF modulator.  There will be versions for the XL, the XE and the 1200XL.

 

  

 

Sincerely

 

Mathy

 

PS sorry, I don't seem to be able to download videos from Facebook.  One of the videos shows how nice the Saturn connector sits behind the hole left by the RF-modulator.

PPS Piotr tells us more about SAVO here on Facebook: https://www.facebook.com/groups/484741565502182/

Edited November 7, 2022 by Mathy

[Peri Noid]

9 hours ago, woj said:

I did study a bit what VBXE could bring in for me and how it is installed, I am mostly after still improving the picture quality (right now having UAV), but also after 80 columns (though quite sure it wouldn't work with MAC/65 for example?) and be able to try the handful of VBXE games. All in all, I am not convinced to be honest, but please just quickly tell me if I got this right:

 

- VBXE replaces GTIA, but only if I use the RGB output of the VBXE, otherwise the stock video output goes from the onboard GTIA that is still doing its thing (and none of the extra video features are available there)?

- The stock GTIA cannot be removed, even if the stock video output is not used? (I am sensing I am getting this one wrong)?

VBXE does not replace anything. It is mounted between ANTIC and motherboard, both ANTIC and GTIA must still stay in the computer.

9 hours ago, woj said:

- It will work fine (putting aside any clearance issues) with UAV, and I can take the CSYNC signal from the composite output of the UAV instead of 4050 without loss of picture quality?

Almost yes. Almost - cause you still need CSYNC. My experiments show, that it's fine if you're not planning to use both outputs at the same time - otherwise, the signal level is reduced and there may be problems, especially with the Composite signal. There is a way tu fix that - the 4050 chip has one buffer not used, it may be utilised to provide the CSYNC signal for VBXE separately to the one for Composite. I don't know how it would work in the presence of UAV.

9 hours ago, woj said:

- I cannot take the pre 4050 CSYNC signal directly from GTIA for the video connector?

It is dangerous for the GTIA - and this signal has no proper parameters.

9 hours ago, woj said:

- There is no way on Earth VBXE will clear my GTIA fixer board (see photo) without building a tower of sockets under the ANTIC VBXE adapter board? And perhaps then not even clearing the case cover?

 

 

It may make no problem at all. Notice, that VBXE is mounted in such way, that first goes the socket, then an adapter, in which ANTIC is placed and then VBXE goes above all of it. So I presume, VBXE may fit just above your GTIA - or you may need just one additional socket. It should fit.

[flashjazzcat]

Does that GTIA board already have two sockets under it? It looks rather tall.

[woj]

Just now, flashjazzcat said:

Does that GTIA board already have two sockets under it? It looks rather tall.

It is tall, but no extra sockets:

 

- precision socket on the PCB

- bottom pins of the GTIA fixer board (*)

- the fixer board

- double swipe socket on the top of the fixer board

- the GTIA chip itself

 

is what builds the "tower". 

 

(*) I actually had to re-solder the bottom pins (required taking off the top socket too) to be nice round fitting the precision socket on the PCB, not sure why the seller sells the boards with the ugly huge square pins. Picture from the WIP, did not take one of the finished thing.

 

I could have soldered in the fixer board directly to the PCB, but it felt very wrong to do so...

[flashjazzcat]

OK - that explains it. I guess the GTIA socket isn't a direct pass-thru so it can't be made like the VBXE adapter (where the socket also provides the pins which push into the motherboard socket) because of the oscillator input having to be isolated.

 

XEs have plenty of room under the keyboard, though, so hopefully VBXE will fit on some stacked sockets. I once put an XE VBXE in a 1200XL and had to mount the header pins on the underside of the VBXE to clear the keyboard on that machine (ironically enough, I didn't want to use an XL VBXE there because there was a PAL GTIA adapter board directly behind the ANTIC socket).

[woj]

2 minutes ago, flashjazzcat said:

OK - that explains it. I guess the GTIA socket isn't a direct pass-thru so it can't be made like the VBXE adapter (where the socket also provides the pins which push into the motherboard socket) because of the oscillator input having to be isolated.

 

XEs have plenty of room under the keyboard, though, so hopefully VBXE will fit on some stacked sockets. I once put an XE VBXE in a 1200XL and had to mount the header pins on the underside of the VBXE to clear the keyboard on that machine (ironically enough, I didn't want to use an XL VBXE there because there was a PAL GTIA adapter board directly behind the ANTIC socket).

No, it's not pass-thru, the CPU adapter for U1MB connectio is though, yet this one has problems clearing up the keyboard on my 800XL, so there I took the bullet and soldered the wires directly to the PCB (somehow I am against this in general, it feels like an ugly irreversible solution, but looking at the VBXE procedures I see I will have to change my opinion on this ;)). Surprises like that make me ask these kind of questions upfront, it is really surprising that such huge (compared to modern equipment) cases still have problems with clearance...

[flashjazzcat]

27 minutes ago, woj said:

Surprises like that make me ask these kind of questions upfront, it is really surprising that such huge (compared to modern equipment) cases still have problems with clearance...

I've just checked my VBXE 130XE here and regardless of whether the Dupont headers at the front edge of the VBXE are placed on the top or underside of the board, I'd say you'll only have room for one stacked socket under the ANTIC adapter before the VBXE and the keyboard get into a heated discussion. There are things which could have been done to make that GTIA adapter lower: low-profile pins on the bottom, and a low-profile socket on the top. That might make everything fit, but devices which use the original VLSIs can only be shrunk so far.

[woj]

1 hour ago, flashjazzcat said:

I've just checked my VBXE 130XE here and regardless of whether the Dupont headers at the front edge of the VBXE are placed on the top or underside of the board, I'd say you'll only have room for one stacked socket under the ANTIC adapter before the VBXE and the keyboard get into a heated discussion. There are things which could have been done to make that GTIA adapter lower: low-profile pins on the bottom, and a low-profile socket on the top. That might make everything fit, but devices which use the original VLSIs can only be shrunk so far.

Thanks Jon! You wouldn't be able to tell me how much actual clearance (in known units of measure) you have between the bottom of the VBXE board and your GTIA (socketed?), would you? Then I could measure my contraption too and would not with some confidence if it all fits or not...

 

EDIT: And of course, I'd still have this problem to solve nicely, see the picture, in your case I am sure the OS rom flat cable happily passes under the VBXE and can take its turns there...

EDIT2: But hold on, what sits "underneath" VBXE is:

 

- socket in the board

- bottom socket / legs of the Antic adapter board

- the adapter board PCB

- top socket of the Antic adapter 

- the Antic itself

 

So this is a similar tower to the one that I have for the GTIA, with the only possible difference that the bottom socket in the Antic adapter is slightly lower than the legs of my GTIA fixer board. So, by deduction, it should wither fit as is, or with one raiser socket underneath the VBXE installation...

Edited November 8, 2022 by woj

[flashjazzcat]

1 hour ago, woj said:

You wouldn't be able to tell me how much actual clearance (in known units of measure) you have between the bottom of the VBXE board and your GTIA (socketed?)

About 7mm between the bottom of the VBXE (i.e. the underside of one of the ICs) and the top of the socketed GTIA. So there's at least one stacked socket in hand.

 

[woj]

38 minutes ago, flashjazzcat said:

About 7mm between the bottom of the VBXE (i.e. the underside of one of the ICs) and the top of the socketed GTIA. So there's at least one stacked socket in hand.

 

Thank you! And that's with one socket to spare as you said, before keyboard becomes an issue. I will measure my contraption inside in the evening and then we'll know 😉

[woj]

So that's not going to fly as it is. The GTIA fixer board raises the GTIA from its socket by 11mm (measured quite precisely). Jon says there is normally 7mm clearance, if I add one precision socket which is 3mm I go up to 10mm, so 1mm short. I could just let it lean on the GTIA and be a bit "bent", but also looking at it, there is very little space between GTIA and the keyboard. And that would be a bodge in any case. So I'd have to lower the fixer board, which is doable as you can see from the pictures, just need to source the low profile legs for it. Not to mention that I'd need to fully redo / reroute the U1MB OS cable. 

 

The other option is to get rid of the socket and solder the GTIA fixer board directly into the PCB, but I am not touching this, the GTIA socket was done twice and the board suffered there enough, it won't make it through another desoldering.

[Beeblebrox]

@woj  not read all posts thoroughly but just to check you have clocked that the vbxe goes in the Antic socket as opposed to the Gtia socket.. Apologies if missed something but the focus here seems to be on the gtia socket. I know you have a gtia fixer mod here but another option is to replace it with an original working gtia if the fixer is causing stacking issues.

[woj]

Yes, we are discussing the GTIA mess, because it stands in the way of the VBXE board mounted in the Antic socket. Yes, I considered swapping around the GTIA from the 800XL, but there the fixer board will just not fit, not by a long shot... So I am better off trying to fix it here.

 

One other option is that I decide (I have not actually committed to VBXE, just doing my homework now) to fit the VBXE in the 800XL instead and play with things there. It might make sense as the picture quality there, even with UAV, is still not as good as on the XE.

[Beeblebrox]

Gotcha.

[Beeblebrox]

BTW you could build a separate relocater board for it all. I did for an 800XL with a simple stereo and aki USB interface that shared the pokey socket. Too tall for the case to close so I rigged up my own solution here. Mine wasn't pretty but it worked. Maybe after a bit of planning a similar but tidier solution would work in your case? 

Edited November 8, 2022 by Beeblebrox

[woj]

16 minutes ago, Beeblebrox said:

BTW you could build a separate relocater board for it all. I did for an 800XL with a simple stereo and aki USB interface that shared the pokey socket. Too tall for the case to close so I rigged up my own solution here. Mine wasn't pretty but it worked. Maybe after a bit of planning a similar but tidier solution would work in your case? 

I am actually also considering something of this sort, just that I am not sure I can do a half-decent job here. Will see, so far it seems that if I can source (or dig out from my cave or adapt something) low profile legs for the fixer board I should be fine, all else is just some (re-)soldering.

[Peri Noid]

I think there's another solution, though you may not necessarily like it. If you're not planning to install Rapidus, you could use an XL adapter. The one which is in the VBXL version. It rotates the card the other way around and moves it over the CPU. There's still a bit of lift needed to fit above the case (cartridge slot) but it's not a big deal.

 

Getting this adapter alone may be a bigger problem.

Edited November 9, 2022 by Peri Noid

[Beeblebrox]

20 minutes ago, Peri Noid said:

I think there's another solution, though you may not necessarily like it. If you're not planning to install Rapidus, you could use an XL adapter. The one which is in the VBXL version. It rotates the card the other way around and moves it over the CPU. There's still a bit of lift needed to fit above the case (cartridge slot) but it's not a big deal.

 

Getting this adapter alone may be a bigger problem.

Just a thought but of the OP is gonna invest in the vbxe board but hasn't bought it yet, then just ordering the vbxe xl version from the outset to install in the way you suggest in the XE would therefore mean it comes with said XL adapter included already? 

Edited November 9, 2022 by Beeblebrox

[woj]

This did cross my mind, only that I was convinced that the board would not have clearance horizontally, I mean that it would go past the case border in the back. This is actually probably the best solution, if I get any problems with that then the kit can go into my 800XL instead and that's it. No plans for Rapidus, especially that I run U1MB in this one.

 

EDIT: Looking the pictures - it indeed might work, just that I would also need to get rid of the U1MB adapter board for the CPU, otherwise I'd need to raise the VBXE adapter quite high to clear the CPU. Uff, why does this have to be so difficult...? 

Edited November 9, 2022 by woj

[woj]

The more I look into this the more hopeless it gets. I can currently see two options to make it more or less elegant and be sure that I will have no bad surprises. One is to design my own adapter board (for my case it would still need to be lifted uncomfortably high), the other one is to relocate it somewhere totally elsewhere using a flat IDC cable with IDC connectors with first replacing the connector on the VBXE with straight or angled pin headers.

[Peri Noid]

7 hours ago, woj said:

Looking the pictures - it indeed might work, just that I would also need to get rid of the U1MB adapter board for the CPU, otherwise I'd need to raise the VBXE adapter quite high to clear the CPU. Uff, why does this have to be so difficult...? 

I have a VBXL so I did some measurements and you'd need to raise it anyway to avoid conflict with the back of the XE case, just to fit above the plastic over the cartridge slot. So if you have an adapter under your CPU, it may stay there. And you'd need to solder wires directly to VBXL not using goldpin connectors. Otherwise - I don't expect problems.

 

Or, there's even easier way - find and buy a correctly working GTIA. And all your problems are gone

Edited November 9, 2022 by Peri Noid