Quick Question about VBXE

[Dmitry]

My main Atari is an Atari 1200XL with U1MB, VBXE and Rapidus.   The VBXE goes out to an hd15 "vga" type plug, but is still RGB and then hooks via VGA cabling to a scan doubler, and then on to a VGA monitor.

 

Most of the time, this is a rock solid display, but if I turn on 80-column mode, such as for using the Last Word, I get some waviness from that VBXE output.

 

It's only that - everything else is rock solid.  What do you all think?  Is it normal?  Does anyone else experience this?  

I cannot fix it, but is it possible to fix?

 

 

[Rybags]

The only difference with 80-col mode is the horizontal resolution is 640 rather than 320.

 

It'd be interesting to see how it looks with bitmap 640 mode though I suspect it'd be the same.

It might be some behaviour from the scan doubler.

Do you have specifications for it?  It might be that the peak to peak voltage is out of range or something and VBXE is exceeding it.

 

I have a couple of video converters, one of which takes the RGB and converts to S-Video (it was created with the Amiga as the target machine).

The p->p voltage the device expects is lower than what VBXE produces so before ever using it I rigged up a voltage divider circuit for each video component and it works fine.

 

Though the question arises, why would yours behave as such only in the hires mode.

 

I also have a scan doubler, GBS 8200 V4 (probably clone), the target audience there mainly being old arcade hardware.

I can't recall it having problems though my main use for VBXE has been the lower res, higher colour situations.

[larryleffaovell]

I've installed a VBXE in my 1088XEL just some weeks ago. Picture is sharp as a razor, even in LastWord.

The RGB cable I'm using is a self built one which leads to scart socket and monitor. I've ensured that every cable that transports a video signal is fully shielded to avoid any interference with wifi signals and alien technology.

 

[Dmitry]

Thanks all.  I am using an old arcade scan doubler, bought off e-bay years ago.  I do have it in a case. 

 

I had forgotten, I actually have an ST connector on the back.  And a cable that converts it from ST style to hd-15.

 

Anyway, on further review, I think the screen is about the same stable in VBXE mode and non-VBXE, which is to say, not perfectly stable.  I only notice it not being "perfect" now because I'm examining it hard, that I can see on the thinnest of horizontal lines, that it has a slight wobble.

 

But stable enough that I wouldn't have noticed - except, for last word has a very noticeable wobble that is unmistakable on the letter that is next to the cursor.  This overall gave me the impression of general waviness.  And btw, it still does. Lol, if I don't concentrate hard, I think the screen is waving, but it is really only that character.

 

Now - examining characters in 40-col mode in Atari DOS, I see that when you type in a character it pops in, moves a bit, and then goes stable.  But after the shaky pop-in it actually remains stable even if the character is next to the cursor.   So, the overall impression in 40-col DOS, is that the screen is stable.

 

Anyway, with this in mind, does the character next to the cursor, wave for you in Last Word? 

 

 

 

 

Edited November 24, 2020 by Dmitry

[drac030]

24 minutes ago, Dmitry said:

Anyway, with this in mind, does the character next to the cursor, wave for you in Last Word? 

Here it does not. But I have a CRT monitor connected straight to the VBXE, no scan-doublers.

Edited November 24, 2020 by drac030

[+Stephen]

37 minutes ago, drac030 said:

Here it does not. But I have a CRT monitor connected straight to the VBXE, no scan-doublers.

Same for me - crystal clear output in all 3 modes, text and graphics.  I'm running into a Sony 20" PVM (20m2mdu).

[Dmitry]

Looks like the most likely thing to suspect is the scan doubler.  I tried a few displays I have that can do 15khz, but they just don't work with VBXE.

I took a look at flashjazzcat video of The Last Word, VBXE, and the GBS-8220 Scan doubler.  While he shaky cam'ed the video the actually underlying display looks rock solid as near as I can tell.  I did try 3 monitors just now, no difference, they all wave that character.

 

I do have other VGA cables, so I'll try them, but I don't expect much, how would a cabling problem wave only a character next to the cursor.

Weird.

 

And...honeslty I don't really understand how any of it would do that, but, my scan doubler is a GBS-8220 or close cousin (don't remember exactly which one)......oh goodness.

 

 

[+DrVenkman]

Could be a power supply issue to the GBS8200/8220. Waviness can be ripple in the current or a ground loop.

[Dmitry]

 

Hard to video this, the video makes it look better than it is, the bouncing is very visible....but anyway, on the one bounce it shows here, it does that all the time.

 

[Dmitry]

@DrVenkman, thanks, I'll try another power supply.

[+Stephen]

17 minutes ago, Dmitry said:

 

Hard to video this, the video makes it look better than it is, the bouncing is very visible....but anyway, on the one bounce it shows here, it does that all the time.

 

Wow - that is strange indeed.  Almost looks like a "bloom" effect you'd get on some CRTs when the tube (or high voltage supply) was going bad.

 

You mention other displays that do RGB not working with the VBXE.  Which displays have you tried, and what are you using as the synch pin?  I know on my Sony PVM, I had to set it to "synch on green" to get it to work.

[Dmitry]

I tried another 5v power supply for the scan doubler, it had no effect.

 

@Stephen, unfortunately I don't have the skill to put together a hardware project, I destroyed about 3 Atari's trying to do various projects, and have given up on that.

 

So, I don't know what was used.  The other monitor's I tried are all flat panels.  One is an NEC Multisync LCD1550M that does scan down to work with a Coco 3.  But those never worked with the VBXE. 

 

The only thing that has ever worked is the scan doubler. I do have a CM-5 RGB monitor, but it has a 9-pin, I don't have an adapter to try it right now.  Potentially that might be the next cheapest thing to try. 

[candle]

what you see there is PLL retrived pixel clock not in sync with video signal generated by VBXE, and pixel data crawl from one discrete point of sampling time to another

it is also possible that your scaller assumes low-res display data - 480x288 for modern "standards" and there is not enough time slots to accuratly capture VBXE output

check if you can enforce 640 or 800 pixels wide horizontal resolution

you either need to change PLL phase or try to auto-adjust it using white text on black background as your test pattern

whatever scaller's software allows

sorry for being too technical

 

[cwilbar]

I believe the CM-5 is an RGBI monitor (Red, Green, Intensity) and is a digital RBG (not analog), like IBM CGA and EGA graphics used.

 

Definitely research this first, as I'm going by memory which isn't as accurate as it once was ?

 

 

[Dmitry]

@candle, thanks for that explanation.  That gives me hope it is the scan doubler. The NEC monitor is constantly telling me this isn't a supported resolution, but I can dismiss the warning once on startup.

 

A long time ago, I bought an ST to SCART cable.  Nowadays people sell SCART to HDMI converters.  I've gone ahead and ordered one.  The ST connector was hooked up to allow for the connection of an ST monitor.  The cable I have goes from ST to HD15.  But I should also theoretically be able to start from the ST connector and go to SCART - I think, anyway.

 

The SCART to HDMI would not only switch me to HDMI, but also have a nice case.  The case on my Arcade scan doubler was made by me and looks like garbage.

 

@cwilbar - thanks, you are correct, that would not have worked.  

 

 

Edited November 24, 2020 by Dmitry

[Dmitry]

One last bit of news, and then the wait.

 

So I do have a GBS-8220.  I put it in a case years ago, and apparently cased over the control buttons.

 

However, that may have been a good thing.   After uncasing it, and taking the OSD out of Chinese /*for the first time*/, I tried setting it to 1024x768.  Didn't work.  Set it to 640x480, didn't work.  Put it back at 800x600, doesn't work. 

 

I've gone through all the cables and put back on the original power supply - and nothing gets it to work at all any longer.  While it will briefly show the Atari screen in a very discolored way and then it falls back to "no signal".  

 

I see I still have the magic touch.  Oh well, like I said, I've got another scan doubler on order.  Crossing my fingers.

 

[Dmitry]

OMG!

 

It actually works, and I needed not to order anything.

 

1366 x 768 mode doesn't have the jumping.  And I cycled through the "SW" button and when I came back to the VGA out, it started working again.

 

I cannot believe it, it all works, haha...amazing.

[Dmitry]

[Dmitry]

OK, for unknown reasons a long time ago I obtained two ST connector to SCART cables.

 

So I got the device pictured above  which is in a nice case and cost $30, it is a generic SCART to HDMI converter.

 

Well, the first cable "OF COURSE" didn't work, but by now I know everything hardware related must first give me a scare, before then working.

 

With my second cable, this converter does work.  It doesn't blink, as the GBS-8220 can in 800x600 mode.  The GBS-8220 didn't have the blink, after I configured it to 1366x768, but id did then have garbage, although perfectly stable garbage on about every screen.

 

This one works entirely...in 80 column mode, it works in regular mode, it's solid and decent.  Probably high end stuff would be more crisp, but I like it, one problem solved.  One quirk, while it has a 1980x1080 output mode, which would match my monitor, I must output to 800x600.  If I output to the monitors native 1920x1080, then it won't hold the picture and constantly goes dark.

 

However, the mode that works - good enough.

 

So I just wanted to report that, in case anyone else wants to pick up one of these cheap converters to take you to HDMI output on your VBXE.

 

Now, as I'm ramping up my use of the Atari, things that I overlooked for years, are now annoying me.  This machine really doesn't "reset" properly and will often glitch into Altirra Basic.  I haven't installed BASIC AT ALL.  And while I'm aware that is loading off the U1MB, which is installed, it isn't selected to do so.

 

I kind of feared installing the U1MB.  I wonder how much trouble it would be to remove it?  Is anyone familiar with the matter know if it is installed in such a way that you can merely pull it, or will wires be soldered on?

 

The machine seems to work mostly OK if I leave it in 65816 mode with DracOS, but I kind of wanted to be able to switch out of that.  

 

[+mytek]

28 minutes ago, Dmitry said:

I kind of feared installing the U1MB.  I wonder how much trouble it would be to remove it?

Not sure why you would want to do that, but all that's required is unplugging the ribbon cables that go to the MMU and OS ROM sockets (then re-install the original MMU and OS ROM chips), and disconnect the 4 wires going to the small header on the U1MB. Hopefully that was done with a female crimp terminal housing - if so just unplug it and leave it dangling.

 

If you aren't going to use the U1MB, I'd be interested in buying it - just PM me .

 

Never mind you probably aren't located in the United States.

 

[drac030]

45 minutes ago, Dmitry said:

Now, as I'm ramping up my use of the Atari, things that I overlooked for years, are now annoying me.  This machine really doesn't "reset" properly and will often glitch into Altirra Basic.  I haven't installed BASIC AT ALL.  And while I'm aware that is loading off the U1MB, which is installed, it isn't selected to do so.

(...)

The machine seems to work mostly OK if I leave it in 65816 mode with DracOS, but I kind of wanted to be able to switch out of that

I kinda have a problem understanding this section. Normally XL/XE OS will drop into BASIC after boot, when Option was not helod down during cold restart. Or are you saying that a WARM reset drops the machine into BASIC?

 

Also, switching the machine "out of that" - out of what?

Edited December 4, 2020 by drac030

[Dmitry]

 

Rapidus and U1MB are likely not working correctly together.  I gathered this from watching FJC videos today, where in some of his videos is he describes the very symptoms my machine is displaying.

 

However, there are likely other solutions that I'm simply not aware of, one quick thought was to remove the U1MB.  

 

But, also, I am now googling a bit, and it seems this altirra basic was flashed onto the U1MB. So, there may be a way to simply unflash all the cartridges - with Altirra basic "removed" there is no longer anyway to have it load in error.  It's quite frustrating to hit reset and have that fail into Altirra basic, or have altirra basic interfere with another load - when I have never installed this basic, and it is not selected to run in the U1MB config.

 

But, now I will investigate merely unflashing it, as a first step, I guess.

 

I'm in Nashville, btw, I'll update my profile.

 

 

 

 

 

 

 

 

 

 

 

 

 

[Dmitry]

5 minutes ago, drac030 said:

I kinda have a problem understanding this section. Normally XL/XE OS will drop into BASIC after boot, when Option was not helod down during cold restart. Or are you saying that a WARM reset drops the machine into BASIC?

 

Also, switching the machine "out of that" - out of what?

A 1200XL does not normally drop into BASIC because it has no internal basic.    I know I'm not telling you anything... not sure how this thread got confusing.   I never selected a basic, never installed a basic, I don't want basic, it should not appear - ever.

 

Someone flashed it onto the U1MB before installing the U1MB, but it is not selected to load in the U1MB config.

 

 

[drac030]

9 minutes ago, Dmitry said:

I never selected a basic, never installed a basic, I don't want basic, it should not appear - ever.

Ok, all clear now.

 

Maybe reflashing the U1MB configuration menu to an uptodate version will help? If there is an option to disable BASIC and it is not effective, it looks like a trivial glitch in the software.

[Dmitry]

Thanks for your help all.  Honestly I started to get frustrated for a second, because it dawns on me, my initial view of how this works, is probably wrong.  I've been wrong a lot.  But it's ok, I'll figure it out, I'm just dealing with some out of date knowledge here.

 

In the old days, if I jammed a cartridge in the slot, I expected that cartridge to load.  And if I didn't jam the cartridge into the slot, I didn't expect it to appear from thin air and load anyway...haha omg....

But honestly no point in getting frustrated, I think you all are right, my initial reaction to pull the hardware is not the first thing to try

 

However, it may be what i need to do, depending upon how this works.

 

I do have an old version of the BIOS I suspect, I think it says 1.22, so maybe I should try a later version.    And later version can suppress basic, but I'm reading in the doc it doesn't always work.  Then again, I should see, maybe it'll work for my purposes.