Fitting and using the VBXE graphics board.

[morelenmir]

I have started this thread to discuss the basic practicalities of going about an install of the reputably excellent VBXE video mod along with its most obvious advantages.

 

From what I have already read it seems there are quite a number of options about how to wire up the output. I would personally consider this the most difficult part of the install, especially to make the work tidy and lasting. Towards that end it seems there are at least three different scenarios; the board can be wired to a 'VGA' socket, an Atari ST 18-pin DIN monitor socket and even a SCART socket.

 

I suppose my first question about this is - do any give a superior display? For instance I have always found VGA - as applied to the XBox360 at least which gives a number of options for its video-out - to offer a far better picture than the SCART implementation. Also, practically it must be far easier to re-work the standard 800XL case for a DSUB/VGA socket than the physically much larger SCART. The same goes for an ST/DIN socket approach, which must be the neatest of all - especially if you directly replace the existing monitor-out socket and reuse its slot.

 

Also, going from another post, I learned the signal output from the VBXE is not strictly speaking 'VGA' but 15kHz RGB. Now, if that was wired in to a standard VGA socket and connected to a modern television or even old CRT PC monitor via a standard VGA cable, would it still work? Or is a converter of some kind required?

 

Another, very basic question is - at the end of the day, is the mod worth the trouble? The basic 800XL can output to composite video and with a little extra work can also output 'svideo'. Does the 'signal' for want of a better term that the VBXE provides substantially improve on that? Would I notice a considerable difference? Also, I am a little unclear on what you actually get. What is the output resolution from the VBXE? Modern LCD televisions tend to do - often very poor - internal upscaling if the picture they are given is not already in the dimensions of their native resolution. Generally speaking does the picture given by the VBXE, even after being treated in this way still better what you get without it? This is perhaps the most pertinent question as - to me at least - the most convincing argument to buy and fit a VBXE is to give connectivity to modern display devices. Towards that end I think a portable LCD television is probably the most cost effective way of getting an 'Atari monitor' these days. I do however, if necessary have an old 15inch CRT monitor that I could use if it offered a better solution.

 

Anyway, I am sure I will think of more things to ask but I will leave it there for now.

Edited May 8, 2015 by morelenmir

[flashjazzcat]

VBXE outputs 15KHz RGB, so upscaling the signal to VGA won't improve the quality: it'll just make it work on a VGA monitor. Upscaler quality varies and there are numerous threads discussing them. But the quality of VBXE through SCART is excellent, and far superior to the stock Y/C output. Users in the USA are faced with the prospect of either using the VGA upscaler (since SCART is rare in the US) or looking for a modern display which will symc down to 15KHz on the VGA input. In Europe, SCART is the best option if you want to use VBXE with a modern flat-panel display.

 

Regarding SCART: you'd put a DIN13 on the Atari end of the cable, not a SCART connector.

 

The best option for the purist is an old 15KHz CRT monitor like the Commodore 1084S or Philips CM8833-II. Since VBXE outputs an analogue signal, an analogue display avoids any problems with analogue/digital conversion and upscaling, guaranteeing a bright, sharp picture. But many TFT/LCD monitors give great results through SCART. There are numerous topics on the forum discussing flat-panels which have been tested with VBXE.

 

The VBXE picture is sharper and has better definition than the legacy Y/C or composite output, period. Some modified machines have splendid Y/C output, but never quite up to VBXE's standard when it comes to geometric accuracy, sharpness and vibrancy.

 

The connectivity issue is an important one too. S-video has fallen out of favour with TV manufacturers, while SCART is still common on European sets. I suppose SCART will be phased out eventually too, but for now SCART is the obvious choice unless you want to use VBXE with an old CRT monitor (which is what I do).

 

Oh... and regarding the placement of the RGB jack: as I said in the other thread, a good place to put it is where the RF modulator (the TV tuner output) used to be. This means you can keep the legacy video jack as well, which is well worth doing. Meanwhile, the RF modulator will not be missed by any but the most masochistic user.

Edited May 8, 2015 by flashjazzcat

[morelenmir]

That is right to the heart of the matter - no, in most cases you can't connect the VBXE to a VGA input. I honestly don't know if my old ~2001-vintage LG monitor would lock on to a 15kHz signal or not. Presumably it will list the input range on the back of the thing So. It looks like a SCART on the TV end is the safest way for me to go. This looks like it will do the job:

 

http://coolnovelties.co.uk/coolnovelties/atari-st-video-cables/39-atari-st-quality-rgb-gold-scart-video-cable.html

 

Now. In regards the connectivity on the PC. I am pretty sold on the 13 (not 18 as I notice I said above!) pin DIN socket - I think even I can make a hole bigger without wrecking it. I THINK... But... I'm a still a bit squeamish about chopping bits off the motherboard on that scale. I only have two 800XL's at best to practice with!

 

One other thing looking at those photographs showed me was the outputs from the VBXE terminate in pin-headers rather than solder pads, which is rather nice. Do you happen to know the Maplin's part number that corresponds to the proper socket?

[Shawn Jefferson]

I personally like the Atari ST Monitor option... Nice to have an Atari branded monitor!

[morelenmir]

I personally like the Atari ST Monitor option... Nice to have an Atari branded monitor!

It would be, although a little pricey I imagine! However that is the charm of FJC's solution - you always have that option at some point in the future.

[Gohma]

In my various dealings with monitors, I (and most of the retro RBG scene) agree that the Sony PVM (or BVM if your lucky and/or rich) is by far the best monitor for any form of old school gaming. Between the sharpness of the display, and it's ability to take almost any form of video, it's a fantastic investment. In my humble opinion, I would do what FJC is suggesting, and if you really enjoy it, get a Sony PVM. Just a fantastic purchase. As a bonus, if you happen to have any other old consoles, they also would be absolutely stunning on it.

[morelenmir]

Many thanks Gohma - I will check that unit out!!! Maybe I can ebay one for relatively little outlay if I am lucky. I am pretty sure I will go with stripping the RF business away and replacing it with the ST-compatible 13 DIN socket. I think I can drill the case successfully. Dremmeling the motherboard itself though,,, that is leaving me feeling a bit queasy to be honest, but as with most things I am sure taking it slowly and calmly are the key. And steady hands!!! Whether I then go for a ST DIN->SCART solution or an ST DIN->VGA will depend on if my old LG monitor will accept 15kHz input.

 

As a matter of interest I got my stock monitor-socket-to-composite-video cable in the post this morning from ebay. It allowed me to start the testing procedure of my 800XL's and try to make one good machine from the three potentially dodgy ones. That process is probably worth a thread of its own as I have encountered a number of issues I would like advice on. However just so far as the monitor socket goes, once I got a working Frankenstein-machine I could instantly see why everyone wants a better solution!!! The image is overlapped at the edges and pretty blurry. In the short term though I am willing to put up with it while I get the "Happy" board, the "Ultimate1MB' and the "SIDE2" set up and working. The VBXE was always going to be the major hurdle to overcome so I will deal with that only when everything else is done.

[morelenmir]

I am almost at the point of installing this now.

 

Have I read the guide right that in the case of an 800XL one needs only remove 'R110' and 'Q8'? I am a little more confused about removing the 'crystal'. On one line the guide says it should be removed and a couple of lines later it says it shouldn't. Given the VBXE v2.1 for 800XL, should one remove the 'crystal' from the motherboard?

 

Also, the guide mentions removing the existing socket for the ANTIC IC. Is this essential or is it just a 'best practice' to replace it with the precision socket that comes with the VBXE?

[+Stephen]

Pretty much mandatory to use the precision socket.

[morelenmir]

Pretty much mandatory to use the precision socket.

 

Fair enough. FJC explained their benefits to me the other day and, reluctantly I had to agree it made sense to fit it despite how much I dislike desoldering sockets!!!

 

Do you know about the 'R110', 'Q8' and 'crystal'-removal situation Stephen?

[+Stephen]

Sorry - I do not know about the installation in an 800XL. I still haven't installed my VBXEs yet

[morelenmir]

Sorry - I do not know about the installation in an 800XL. I still haven't installed my VBXEs yet

 

No worries! I've been putting it off myself to be honest. I'm finding getting back in to electronics strangely addictive though, despite the frustrating moments. Having done my festive repair of the "SimpleStereo" I only have the VBXE left to get my fix from!

[morelenmir]

I have done some reading this evening about the VBXE firmware. Do I understand it right when the guide says with the right flash it acts as a 256 k memory upgrade? Can you actually use it as a RAM expansion? How would that interact with the "Ultimate1MB"?

[flashjazzcat]

Yes, the R core works like a 256KB PORTB RAM expansion and no it doesn't interact with Ultimate 1MB: use either or. Not sure offhand which gets precedence if both are present but having both active is completely pointless.

[morelenmir]

Yes, the R core works like a 256KB PORTB RAM expansion and no it doesn't interact with Ultimate 1MB: use either or. Not sure offhand which gets precedence if both are present but having both active is completely pointless.

 

Absolutely. Its strikes me as an extremely cool side-feature. One use might be as a dedicated ramdisk say, leaving the whole "Ultimate1MB" purely for programming.

 

I am sure you will be able to tell me, FJC if 'R110' and 'Q8' are the only things I need to remove on a 800XL motherboard for the VBXE? Or does the 'crystal' also need to go - but not be attached to the VBXE? The manual is a little confusing on this point.

[flashjazzcat]

Absolutely. Its strikes me as an extremely cool side-feature. One use might be as a dedicated ramdisk say, leaving the whole "Ultimate1MB" purely for programming.

I think you misunderstand: the two RAM upgrades are mutually exclusive and absolutely cannot be used simultaneously.

 

I am sure you will be able to tell me, FJC if 'R110' and 'Q8' are the only things I need to remove on a 800XL motherboard for the VBXE? Or does the 'crystal' also need to go - but not be attached to the VBXE? The manual is a little confusing on this point.

I don't have access to an 800XL or the install manual at this moment but I only remember I followed the guide: the master crystal needs to be removed from the motherboard and the oscillator output of the VBXE connected to the two holes it left. VBXE then provides the master clock for the entire machine.

[morelenmir]

I think you misunderstand: the two RAM upgrades are mutually exclusive and absolutely cannot be used simultaneously.

 

 

I don't have access to an 800XL or the install manual at this moment but I only remember I followed the guide: the master crystal needs to be removed from the motherboard and the oscillator output of the VBXE connected to the two holes it left. VBXE then provides the master clock for the entire machine.

 

No, I get you FJC - I just suggest the ramdisk idea as one use of an extra 256k, although I understand it cannot be used in this way.

 

That now makes sense in regards the clock.

[morelenmir]

I now have a question about attaching the pin-headers.

 

Given it would be hard to remove the VBXE board after soldering its precision-engineered socket to the motherboard, is it a good idea to populate all the pin-header mounts ahead of time? I prefer to connect the various boards via DuPont plugs->pin-header rather than soldering wires directly to the daughter-board. I also know I do not need all of the connectivity the VBXE offers - like the diagnostic JTAG socket and so on. Also, given the positioning of the VBXE relative to the underside of the keyboard there is not a lot of space and I think for there to be room for plugs to attach I will need to bend their pins 90 degrees to the board.

 

How do you chaps go about arranging the pin-header connectivity in preparation for installation? Do you just solder wires directly to the VBXE?

[flashjazzcat]

Given it would be hard to remove the VBXE board after soldering its precision-engineered socket to the motherboard, is it a good idea to populate all the pin-header mounts ahead of time?

Whaaaaaat!!?? Solder the precision socket to the motherboard, not the actual Antic adapter. The VBXE and adapter will then be easily and safely removable. Antic adapter plugs into precision socket, which is the only thing permanently attached to the motherboard.

 

I prefer to connect the various boards via DuPont plugs->pin-header rather than soldering wires directly to the daughter-board. I also know I do not need all of the connectivity the VBXE offers - like the diagnostic JTAG socket and so on. Also, given the positioning of the VBXE relative to the underside of the keyboard there is not a lot of space and I think for there to be room for plugs to attach I will need to bend their pins 90 degrees to the board.

Use Dupont connectors and solder right-angle header pins to the appropriate places on the VBXE board. This will keep everything low-profile and there will be no clearance issues.

 

How do you chaps go about arranging the pin-header connectivity in preparation for installation? Do you just solder wires directly to the VBXE?

No, no, no, no. Although some people will say yes. Use Dupont connectors, keep it neat, and be happy you did so in the future.

[morelenmir]

Whaaaaaat!!?? Solder the precision socket to the motherboard, not the actual Antic adapter. The VBXE and adapter will then be easily and safely removable. Antic adapter plugs into precision socket, which is the only thing permanently attached to the motherboard.

 

:) No... I get what you mean FJC, but I was going from what old Lotharek says in the guide:

 

3. Solder into ATARI board VBXE ADAPTER

 

NOTE: Do not remove bottom precision 40 pin socket from VBXE adapter whilst soldering !

 

 

I assumed he had attached it permanently and it would damage the board if you pulled it off. If it is safe to remove it then that will certainly make the job of soldering it down a lot easier - although I am not looking forward to de-soldering the old one. Chip-Quik may be the cats whiskers for SMT components but I have twice accidentally lifted pads and traces when using it with through-hole stuff like sockets.

 

Use Dupont connectors and solder right-angle header pins to the appropriate places on the VBXE board. This will keep everything low-profile and there will be no clearance issues.

 

I have been bending my own up until now - which works, but does not leave a lot of pin for the plugs to attach. I will see if ebay has any of the pre-angled type. Probably for pennies I dare say! Can you get double-row, angled ones also? That would be cool for J1 and J2 as highlighted on the attachment.

 

No, no, no, no. Although some people will say yes. Use Dupont connectors, keep it neat, and be happy you did so in the future.

 

Yep. I agree. Lotharek's boards are too visually attractive to bollux them up with soldered wires!!!

[flashjazzcat]

:) No... I get what you mean FJC, but I was going from what old Lotharek says in the guide:

 

I assumed he had attached it permanently and it would damage the board if you pulled it off. If it is safe to remove it then that will certainly make the job of soldering it down a lot easier - although I am not looking forward to de-soldering the old one. Chip-Quik may be the cats whiskers for SMT components but I have twice accidentally lifted pads and traces when using it with through-hole stuff like sockets.

The thinking is probably that leaving the adapter in the socket while soldering the latter to the motherboard will ensure pin alignment remains true and the pins on the Antic adapter aren't bent... I'm not sure. In any case, if the Antic adapter doesn't push right back into the precision socket once the socket is soldered in, something got horrifically melted.

 

I have been bending my own up until now - which works, but does not leave a lot of pin for the plugs to attach. I will see if ebay has any of the pre-angled type. Probably for pennies I dare say! Can you get double-row, angled ones also? That would be cool for J1 and J2 as highlighted on the attachment.

You won't get far bending the header pins, and the right-angle ones do indeed cost pennies. Although I've put dual-row right-angle headers on J1 and J2 here, you can get away with a single row on the outer pins on J1 and leaving off J2 altogether if you like:

 

 

Lotharek's boards are too visually attractive to bollux them up with soldered wires!!!

Although Lotharek doesn't seem to think so, since he solders wires directly to the holes.

[morelenmir]

You won't get far bending the header pins, and the right-angle ones do indeed cost pennies. Although I've put dual-row right-angle headers on J1 and J2 here, you can get away with a single row on the outer pins on J1 and leaving off J2 altogether if you like:

 

Many thanks for the photo FJC - this is exactly the kind of information I am after; the practicalities and 'how to' aspect. Once you know how a thing should look it gives a huge degree more confidence than even an written FAQ or answer.

 

The "Ultimate1MB" setup screen has an entry for setting the address in memory where the "VBXE" will reside. I think that is communicated via 'J1', although in Lotharek's guide he describes how to short the pins so you set this address permanently. I notice in your example here however you have only attached the one cable from the "Ultimate1MB", which I think must be the simple ON\OFF signal. Do you usually not bother with address setting?

[flashjazzcat]

The "Ultimate1MB" setup screen has an entry for setting the address in memory where the "VBXE" will reside. I think that is communicated via 'J1', although in Lotharek's guide he describes how to short the pins so you set this address permanently. I notice in your example here however you have only attached the one cable from the "Ultimate1MB", which I think must be the simple ON\OFF signal. Do you usually not bother with address setting?

VBXE base address is controlled by the Ultimate BIOS setting in the photo. The WP pin just controls the address decoding, so it's D6xx, D7xx, or disabled. Just one wire needed.

Edited June 11, 2015 by flashjazzcat

[morelenmir]

VBXE base address is controlled by the Ultimate BIOS setting in the photo. The WP pin just controls the address decoding, so it's D6xx, D7xx, or disabled. Just one wire needed.

 

Ahhh... So the address is set in the "Ultimate1MB", the only communication it has via 'J1' is whether to switch on or off?

 

In regards connecting the 13-pin din socket to the SCART on my TV, would this cable be appropriate do you think?

 

http://www.ebay.co.uk/itm/Atari-ST-High-Quality-RGB-GOLD-Scart-AV-Lead-Video-Cable-TV-Lead-2mtr-/250978089310

[flashjazzcat]

Ahhh... So the address is set in the "Ultimate1MB", the only communication it has via 'J1' is whether to switch on or off?

No. The signal from the WP pin simply tells the address decoder when the VBXE control registers are addressable. So, it will do this (via logic 0 or 1, I don't know which) either when the CPU addresses D6xx, D7xx, or not at all, depending on the Ultimate BIOS setting (which is - internally - two bit: one bit is an on/off toggle, and the other selects $D6/D7).

 

In regards connecting the 13-pin din socket to the SCART on my TV, would this cable be appropriate do you think?

Yes: that looks like it should work.