TT030 VGA picture quality

[JonB]

Hi

Having a problem with a TT030 I just acquired.

When connected to a VGA LCD monitor the picture does not fill the screen properly (it's squashed to the left) and there seems to be a lot of interference. The machine is working, but the display makes it unusable - the resolution doesn't look right and character rendering is kind of blocky; it basically looks crap.

I have not opened it up yet to check for poor connections, but can someone tell me if this is normal? The monitor works fine on an ST in high-rez mode (using an adapter), because it is old enough to be able to synch right down to 60hz. I really don't want to be sending it back as faulty... since they are so rare...

Thanks

JonB

[Frank B]

Hi

Having a problem with a TT030 I just acquired.

When connected to a VGA LCD monitor the picture does not fill the screen properly (it's squashed to the left) and there seems to be a lot of interference. The machine is working, but the display makes it unusable - the resolution doesn't look right and character rendering is kind of blocky; it basically looks crap.

I have not opened it up yet to check for poor connections, but can someone tell me if this is normal? The monitor works fine on an ST in high-rez mode (using an adapter), because it is old enough to be able to synch right down to 60hz. I really don't want to be sending it back as faulty... since they are so rare...

Thanks

JonB

My TT offsets the picture slightly. I use an old vga monitor with digital settings. You might need to adjust the position a bit.

Frank

[wongck]

It is unfortunate that the VGA specifications changed after the TT came out.
So the VGA output will not be looking "correct" against the standard spec.

At TT medium rez, on my TT, the VGA is moved to the left with a larger border on the right
The lower part of the desktop extents right to the bottom.

I am using a standard LCD panel, which is fortunate that the TT VGA sockets fits.

[DarkLord]

Ditto, when I had my TT030 I used a Nec 3D with it and I always had to use the
controls to move and center the TT's picture.

Not sure about the interference part - I never had any troubles with that.

[Cyprian]

Ditto, I also have an old LCD and same as DarkLord, I use the controls to center and stretch TT desktop screen horizontally.

It is unfortunate that the VGA specifications changed after the TT came out.
So the VGA output will not be looking "correct" against the standard spec.

this is an 'official' story.
unofficial story is that was done on purpose. TT video pixel clock is generated from main clock, in order to have synchronized main memory bus with TT Shifter. I guess it is done in that way due to cost cutting.
Finally TT pixel clock is 32MHz, and is higher than VGA standard - 25MHz.

VGA horizontal frequency is fixed at ~31.468 kHz and with TT 32MHz video pixel clock, every line has 1024 pixels (in ST MID/HIGH / TT MID mode), 640 pixels are for desktop and 384 are border.

TT 32MHz / 31.5 kHz = 1024 pixels: 640px screen + 384px border
VGA 25MHz / 31.5 kHz = 800 pixels: 640px screen + 160px border

Therefore TT architecture just forces VGA to show so huge border. That issue is fixed in Falcon, it uses 32MHz for TV mode and 25MHz for VGA mode.

[lp]

The PTC1426 VGA monitor from Atari has a switch on the back "VGA or TT" mode and it corrects the aspect ratio. Generally the TT looks like crap on an LCD. Most equipment looks like crap unless you use the native mode of the LCD. I have 2 LCD's on my TT, one for the TT boot up, looks awful, then a second one for the gfx card which drives the monitor at its native mode, then it looks awesome.

[JonB]

Oh dear. I am going to have to try and find a video card for it, aren't I?

[Klapauzius]

You should consider a good CRT monitor, say 17" sized.

In my experience, once you have dialed in the picture geometry (width), the TT produces an acceptable picture on a CRT VGA monitor. I still had a bit of interference on the CRT screen (slight vertical 'ghostly' lines), but compared to the horrible quality on a LCD screen it looked ok and was definitely usable in TT medium.

[JonB]

Thanks for that Klaz... wish I'd known before I bought it! Oh well.

Actually, the guy who sold it (calimero) has been very patient with me. In fact he has been great!

[mdivancic]

It may be easier to snag a PTC1426 VGA monitor then to find a video card. I've been trying to get one for about 2 years. You could also get a Atari TTM195 monochrome monitor. B & C ComputerVisions (myatari.com) has reconditioned TTM194/5 for $50 and PCT1426 for $125. I've been thinking of going the monochrome route myself.

[wongck]

Oh dear. I am going to have to try and find a video card for it, aren't I?

That would be the way to go.

[wongck]

It may be easier to snag a PTC1426 VGA monitor then to find a video card. I've been trying to get one for about 2 years. You could also get a Atari TTM195 monochrome monitor. B & C ComputerVisions (myatari.com) has reconditioned TTM194/5 for $50 and PCT1426 for $125. I've been thinking of going the monochrome route myself.

Yeah, but you get higher resolutions & more colours with a graphic adapter.

[mdivancic]

Yeah, but you get higher resolutions & more colours with a graphic adapter.

Very true, but if you can't find a card you got nothing!

[calimero]

I used TT on Samsun 753s monitor (CRT) and you can move picture in middle of screen so it looks ok (and also stretch it until right black border disappear).

On LCD monitor, after you center picture, you need to manually set PIXEL PHASE (or something like that) to remove interferences! I try TT on few LCDs and AUTO button on LCDs _can not_ set picture properly! you need to set it manually.

There was graphics card in that TT but when I bought it I need to give it away and my plan was to buy TTM194/5... but I sold it to pay for SuperVidel

JonB, hope it will serve you well!

[JonB]

Hi calimero

I had a play with one of my old monitors and got it centred, hooray! Much better now, but, like you, I think I will try and get a proper TT monitor. I found the Ethernet adapter, it was well hidden. Lucky I kept all the packaging! Hope the payment has arrived OK. Please let me know if not. I am now wondering what to do next... as you know, it is all setup for mint and some other stuff but I would like to start again so I understand it better. I guess this means copying all files onto a card (I have UltraSatan here, so if I can get that working I can backup) and then reformatting the CF card (or get another one) for a clean install. First though I need to identify what all this software actually is...

..and of course there's my favourite bit which is when I open her up for a good look inside!

[dhedberg]

OK, it's time to revive a very old thread again. For everyone with a TT that wants a perfect picture on a modern LCD when using the internal TT-Shifter, go buy an OSSC: https://www.videogameperfection.com/pro ... converter/

I've said it before, this thing gives full control over the video signal. It can sample the 32MHz pixel clock of the TT to perfection. Picture proof attached (TT-Medium on a Benq BL912 - without the OSSC the picture looks like crap!). So don't try and find the perfect monitor, just buy the OSSC and use ANY monitor for your TT.

[calimero]

^
I can not open https://www.videogameperfection.com !
Is this same thing: http://junkerhq.net/xrgb/index.php?title=OSSC ?

Where did you buy it and how much does it cost?

[dhedberg]

I can not open https://www.videogameperfection.com !

Wow. Seems like the site went down right after I posted the link. The site is probably under attack or something. Check it again in a few ours/days.

Is this same thing: http://junkerhq.net/xrgb/index.php?title=OSSC ?

Yes!

Where did you buy it and how much does it cost?

https://www.videogameperfection.com/pro ... converter/
That's the official site where you buy it.

[susher]

It looks like the site's hosting hasn't been renewed and it's gone.

[wongck]

Wow. Seems like the site went down right after I posted the link. The site is probably under attack or something. Check it again in a few ours/days.

No... just that all TT owner started clicking on the link to check it out.




It's just that they have not paid their hosting company.

[Cyprian]

OK, it's time to revive a very old thread again. For everyone with a TT that wants a perfect picture on a modern LCD when using the internal TT-Shifter, go buy an OSSC: https://www.videogameperfection.com/pro ... converter/

I've said it before, this thing gives full control over the video signal. It can sample the 32MHz pixel clock of the TT to perfection. Picture proof attached (TT-Medium on a Benq BL912 - without the OSSC the picture looks like crap!). So don't try and find the perfect monitor, just buy the OSSC and use ANY monitor for your TT.

looks nice

[mikro]

Really nice idea. I read about the OSSC here: http://www.atari-forum.com/viewtopic.ph ... 71#p346128 and it got me interested (but like evil, equally disappointed with the pause between interlace/non-interlace switching). But since the TT doesn't suffer from such issues (no interlaced modes there ;)), this got me interested again!

[dhedberg]

Yeah, the OSSC is not ideal for the Falcon030, but good enough I'd say. If you want a pretty much ideal monitor for the Falcon030 have a look at the Dell UltraSharp U2410. Just posted about it here: http://atari-forum.com/viewtopic.php?f= ... 58#p353446

[susher]

It looks as though their web hosting is dead. You can find out via their Facebook page.

https://www.facebook.com/videogameperfection/

[dhedberg]

Good to know. Thanks! Hopefully it'll be all sorted out soon.