VBXE 2

[pps]

Hello Sascha

 

Berlin I guess.

 

 

Yes, I have been there too on Friday. But another part of town. In fact, another country more than 20 years ago...

 

Watch the first minute:

 

As far as I know dl7ukk lives in Treptow-Koepenick the green part of Berlin in the south east. You can try to get him via cb radio (or better in the so called "Amateurfunk"). His skip should be known (hint: have a look at his forum name) Oh I found his band: 145,475 MHz

Edited October 19, 2010 by pps

[ctirad]

Excuse me, maybe it was discusse before, but it is possible to switch the VBXE2 to produce YPbPr component output without additional converter? After quick look at the video DAC specifications I see it is capable to produce either RGB or YPbPr...

[Rybags]

Candle has done a 30 KHz RGB version that works on modern monitors, but needs a ~ 28 Mhz crystal rather than the 14.

 

Not sure about Component... by default VBXE doesn't actually have anything to do with the CSync signal, you tap it yourself elsewhere off the motherboard and run it to whatever monitor port you're using.

But in theory VBXE could deduce where the Sync signals are required anyway since it reads the AN0-2 bus signals.

[rchennau]

Rybags (and anyone else)

I'm going to be a lucky recipient of the (edit) one of the (/edit) final 10 VBXE units left. I am very excited but also kind of worried. I am in the U.S. and thus have the NTSC challenge. That is how do I (cheaply) take the RGB signal and display it on my Toshiba LCD that accept DVI and component? I'm not a video expert so I'll need help from the good folks on this forum. Specifically what have others in the U.S. done to hook up VBXE? Ideally I'd like the Atari 600XL with the VBXE to be a showpiece in my living room vs. stuck next to my computer with a VGA monitor...

 

Help?

 

 

 

Candle has done a 30 KHz RGB version that works on modern monitors, but needs a ~ 28 Mhz crystal rather than the 14.

 

Not sure about Component... by default VBXE doesn't actually have anything to do with the CSync signal, you tap it yourself elsewhere off the motherboard and run it to whatever monitor port you're using.

But in theory VBXE could deduce where the Sync signals are required anyway since it reads the AN0-2 bus signals.

Edited October 21, 2010 by rchennau

[Rybags]

You're buying 10 of them?

 

I've got one of these RGB -> SVideo convertors and so has one or two others http://www.amigamaniac.com/RGB_to_PAL_NTSC_adapter.html

 

I've not tried mine yet, you have to use a 7 Volt or higher DC power supply to it. Plus you'll probably need to put voltage dividers on the RGB inputs to lower the voltages slightly.

 

Component isn't RGB, plus the RGB from VBXE is at a slower scanrate so TVs and monitors that accept VGA won't necessarily work with VBXE.

 

You're easiest way out is to get a colour monitor to suit an ST or Amiga because the signals used are virtually the same.

 

There are also boxed RGB convertors around that can do conversion to S-Video, as well as scandoublers that would allow you to use a modern monitor, but they're $80 upwards.

[rchennau]

I think this might be a nice solution:

 

CGA/EGA/YUV to VGA Arcade HD-Converter PCB (GBS-8220)

 

From what I can tell it will take RGBHB but it also may take RGB. Good price as well.

 

 

 

 

 

You're buying 10 of them?

 

I've got one of these RGB -> SVideo convertors and so has one or two others http://www.amigamani...SC_adapter.html

 

I've not tried mine yet, you have to use a 7 Volt or higher DC power supply to it. Plus you'll probably need to put voltage dividers on the RGB inputs to lower the voltages slightly.

 

Component isn't RGB, plus the RGB from VBXE is at a slower scanrate so TVs and monitors that accept VGA won't necessarily work with VBXE.

 

You're easiest way out is to get a colour monitor to suit an ST or Amiga because the signals used are virtually the same.

 

There are also boxed RGB convertors around that can do conversion to S-Video, as well as scandoublers that would allow you to use a modern monitor, but they're $80 upwards.

[candle]

Richard:

i know this threar is way to long to read it all

[Rybags]

Got my RGB to S-Video/Composite adaptor working http://www.amigamaniac.com/RGB_to_PAL_NTSC_adapter.html

 

The chip expects .714 Volts P->P on the RGB inputs, but VBXE does .75.

 

So, I put in a voltage divider on each of the inputs.

 

For now, R1=75 Ohms, R2=1.2K which should bring it down to about .705 V. I'll have to do a luma bar program or something to check that the range is right.

 

The convertor needs a DC source of between 7-35 Volts, so I've mounted it on a PCI bracket and it'll just go inside the PC. I'll be using it through my capture card, so it's no great problem.

 

Here's a few sample capture pics.

 

Edited October 28, 2010 by Rybags

[Rybags]

 

Still a little tidyup work needed, then it can go inside the computer.

[Jacques]

Why to convert RGB to worse quality S-Video/Composite?

[Rybags]

For doing video and stills captures, plus allows me to use it on my LCD monitor instead of the 1084 if needed.

[Jacques]

Oh, I get it I prefer LCD-TV 17" monitor for all kind of retro-computing as it has VGA, SCART (RGB for VBXE), S-video, composite, etc. No picture quality loss

[Rybags]

Yes... the captures are a little grainy (zoom into DOS one), but streets ahead of the monitor output from a non-VBXE machine.

[candle]

little something (very preliminary version, so excuse me)

 

http://spiflash.org/atari/vbxe-robbo.xex

 

only few planets are linked, and some things might work wrong, as i'm guessing what original author had on mind

some bugs were possibly introduced due to cross-compiling it (original was written in preliminary version of Quick Assembler, with lots of semigraphical chars in source code)

 

to do: animations, better graphics tiles (these i've used are from open-robbo) - ofcourse source code will be included in next release of vbxe pack

 

Sebastian

[candle]

can't edit, so new one

 

http://www.youtube.com/watch?v=iWyurCGusz4

[rchennau]

First: I should read my own post / research about converting RGB to YUV.

Second: As luck would have it for the last ten years I've been staring at a NEC MultiSync LCD2000. It has yet to fail so it has been my main monitor for a decade. I always knew that the NEC LDC2000 had a weird cable that went from VGA from the computer to whatever it was on the back. I never thought much of it. Today I looked at the manual and to my surprise the NEC has RGB input! I found the manual and sure enough the cable was a BNC to VGA cable.

 

Thus the back of the monitor has BNC connection ports labeled: H/CS, VS, R, G/Sync, B!

The manual states the lowest horizontal sync rate is 24.0 khz.

I understand that VBXE 2 only outputs 15 khz by GITA. But did I read in this thread there is someway to double that up to 30 khz?

 

If so then I won't need a RGB to YUV convert for the near term. I can use my NEC LCD2000.

 

Am I getting this right?

[Rybags]

If you did the mod for VBXE @ 30 KHz, then it would work on practically any VGA monitor.

 

But of course, you're still at 60 Hz frame rate which is a bit flickery, PAL is worse off because most monitors are pretty poor at doing 50 FPS.

 

Thinking about it, the older monitors are probably better for 60 Hz because that was actually the standard for a while, and they tend to use larger/longer persistence pixels.

[rchennau]

Thanks RyBags. But exactly what do I have to do to mod the VBXE to get 30 KHz? A

 

 

If you did the mod for VBXE @ 30 KHz, then it would work on practically any VGA monitor.

 

But of course, you're still at 60 Hz frame rate which is a bit flickery, PAL is worse off because most monitors are pretty poor at doing 50 FPS.

 

Thinking about it, the older monitors are probably better for 60 Hz because that was actually the standard for a while, and they tend to use larger/longer persistence pixels.

[Rybags]

At the least, it's a new core by candle and you have to change to a 28 MHz crystal (same as an Amiga).

 

Not sure if the core remains fully compatible, to fit new stuff in some cases they have to cut on existing features.

[candle]

Firstly,

VGA core is by Electron, not me

I'm just that PITA that made him do it

Secondly,

60hz (or even 50Hz) on LCD monitor is not an issue! nothing flickers - at all

[Dropcheck]

Firstly,

VGA core is by Electron, not me

I'm just that PITA that made him do it

Secondly,

60hz (or even 50Hz) on LCD monitor is not an issue! nothing flickers - at all

 

 

Forgive me if I'm abit dense, but after reading your mod for vga out is it just a couple of wire connections or a core upgrade or a crystal change or what for NTSC models? All I have is a stone cold simple VGA monitor with a switch box for multiple VGA inputs. Well I do have a TV/Composite/S-Video to VGA converter but quality does suffer some.

[Rybags]

Crysal change = you have to desolder the 14 MHz one and solder back in a 28 MHz one.

 

Core upgrade, I would assume is just flashing a new core as per normal. I'd also assume you'd do that, then set the new one as the boot default before doing the crystal.

 

Wiring... fairly sure candle mentioned the need to add a connection or two for Sync - obviously makes sense since the default 15 KHz sync is sourced from GTIA, VBXE in default mode plays no part in driving it.

 

 

I've had a change of mind for my video convertor... I'm thinking now I'll just put it into a project box.

Don't see the sense in powering it all the time from the PC - think I'll just drive it from a wall-wart and put a power switch on the box.

 

Another possibility, if it'll fit is to put it into the XM301 case with my SIO2SD (which is still sitting bare).

Edited October 30, 2010 by Rybags

[rchennau]

Dropcheck: if you have the same challenge as me then this is what we will need:

 

A sawtooth/triangle wave oscillator

A 30 kHz crystal

 

What I don't quite understand is why I need both a 30 kHz crystal AND a 30 kHz oscillator. O get the oscillator is generating the clock frequency needed to drive VGA out. But what is the point of the 30 kHz crystal?

[Rybags]

Why would you need those? Do 30 KHz crystals even exist? They'd probably be 6 inches long if they did.

 

The "modded" VBXE generates the needed signals, the reason the 28 MHz crystal is needed is that the pixel clock speed is twice normal (remember 640x240 mode = ~14 MHz) since it's doubling up each scanline.

[rchennau]

That is my point. What is needed to mod the VBXE to gernerate the clock signal so a VGA will synch? Is it just adding the 28 kHz crystal in place of the 14 on the VBXE?

 

I thought Candle mentioned one would need to grab the synch signal from somewhere else a the GITA was only generating at 15 kHz.

 

Forgive if this reads a bit ignorant because honestly I am! .

 

Maybe all my questions may help someone who is even more of a noob than me.

 

Thanks RyBags for your help. Candle as well!