Artifacting "Color"

[oo7]

So, unless Im going crazy I remember at some point in time my old 8-bit under GR.8 artifacting would look blue & orange. Then at some points the artifacting was green/pink.

 

Does anyone else remember this?

 

Can anyone explain why the difference?

 

Just something that has bugged me now and then for like the last 30 years or so lol

[José Pereira]

1 minute ago, oo7 said:

So, unless Im going crazy I remember at some point in time my old 8-bit under GR.8 artifacting would look blue & orange. Then at some points the artifacting was green/pink.

 

Does anyone else remember this?

 

Can anyone explain why the difference?

 

Just something that has bugged me now and then for like the last 30 years or so lol

The same but different machines, ones green&pink while others blue&orange.

[Goochman]

800 was orange/blue and XL/XE was green/blue.  From what I understand its based upon the color cycle or such.  The XL/XE was shifted a bit hence the artifact colors changed.

 

My technical explanation is probably 100% wrong but the basic idea is right

[+DrVenkman]

Check out this now-old thread for lots of good info and examples:

 

https://atariage.com/forums/topic/204355-artifacting-isnt-it-weird

[oo7]

@Goochman I have only ever owned XL and XE systems and Im sure my 600 and 800 XLs all were blue/orange and Im sure some of my XE were Blue/Orange and Im sure some of and my current xe are green/pink. I wish they were all blue orange lol

 

@DrVenkman Will def read, thank you!

[hasanc]

Check out Altirra Hardware Reference Manual Appendix C.3 for an in depth technical explanation about NTSC artifacting: http://www.virtualdub.org/downloads/Altirra Hardware Reference Manual.pdf

[Krenath]

Of all the NTSC machines I've messed with:

• 400/800 artifact colors are blue/green.  Games like Ultima III were designed with this in mind.
• XL machine artifact colors are purple/green.  
• XE machine artifact colors are red-orange/blue.  Games like Flight Simulator II were designed with this in mind.

Of course, if you mess with the color pot, this can shift significantly.  

And, as we found out somewhat recently, if you put a UAV or Super Color CPU Card (which uses the UAV circuit) into an old 800, you'll change the artifacting from 800-style to XL-style.

I haven't played with a PAL machine to see what artifacting looks like on those.
 

Edited March 20, 2021 by Krenath

[+DrVenkman]

5 minutes ago, Krenath said:

Of all the NTSC machines I've messed with:

• 400/800 artifact colors are blue/green.  Games like Ultima III were designed with this in mind.
• XL machine artifact colors are purple/green.  
• XE machine artifact colors are red-orange/blue.  Games like Flight Simulator II were designed with this in mind.

Flight Simulator II was released significantly before the XE machines were introduced. My copy has (c) 1984 on the box, during the XL era of machines. Here's a pic of what it looks like running on one of my 800's with stock composite video.

 

 

 

[Krenath]

Hard to tell from the pic, but it sort of looks like you're getting magenta/green on the artificial horizon ball.  Interesting. 
If I try to adjust my 800 to get similar artifact colors, everything else looks really odd.  The blue notepad/BASIC screen is far from blue.  I don't seem to be able to get any of my 800s to display like that.  

When I run Flight Simulator on my 800s, the artificial horizon has blue sky and green ground.  

Faicuai insists that it should be blue and orange because he has a plane that has the same colors.

I wonder just how much variance in tolerance in components there were back then, and how often they changed.  The three operational 800s I have currently have different manufacturers of just about everything.  Resistors, capacitors, even the main VLSI ICs are all over the map.

Edited March 20, 2021 by Krenath

[+David_P]

Are there differences between the disk and cart version of FS II?

[oo7]

21 minutes ago, David_P said:

Are there differences between the disk and cart version of FS II?

noth the main game though you can get more scenery discs if memory serves for disk version

[Bobo Cujo]

5 hours ago, Krenath said:

Of all the NTSC machines I've messed with:

• 400/800 artifact colors are blue/green.  Games like Ultima III were designed with this in mind.
• XL machine artifact colors are purple/green.  
• XE machine artifact colors are red-orange/blue.  Games like Flight Simulator II were designed with this in mind.

Of course, if you mess with the color pot, this can shift significantly.  

And, as we found out somewhat recently, if you put a UAV or Super Color CPU Card (which uses the UAV circuit) into an old 800, you'll change the artifacting from 800-style to XL-style.

I haven't played with a PAL machine to see what artifacting looks like on those.
 

The UAV has a trim pot specifically for modifying the artifact color value - I have one in my 800XL and I purposely set it to Orange/Blue.  (There's a test program somewhere in the forums (uav.xex) for calibrating this...)

[leech]

7 hours ago, DrVenkman said:

Flight Simulator II was released significantly before the XE machines were introduced. My copy has (c) 1984 on the box, during the XL era of machines. Here's a pic of what it looks like running on one of my 800's with stock composite video.

 

 

 

I do believe the disk version is for the 800 color scheme, the cart was for the XE era machines.  Ah artifacting, seems to really just keep coming up, I've started many threads on it myself

[Mazzspeed]

7 hours ago, DrVenkman said:

Flight Simulator II was released significantly before the XE machines were introduced. My copy has (c) 1984 on the box, during the XL era of machines. Here's a pic of what it looks like running on one of my 800's with stock composite video.

 

 

 

I must say, it's refreshing to see a CRT!

[leech]

51 minutes ago, Mazzspeed said:

I must say, it's refreshing to see a CRT!

Yeah, I prefer hooking my Atari's up to my Commodore monitors   I've been looking recently at getting one of that model as well... 1702?

[Mazzspeed]

28 minutes ago, leech said:

Yeah, I prefer hooking my Atari's up to my Commodore monitors   I've been looking recently at getting one of that model as well... 1702?

I think there was a 1701 and a 1702, not too sure if there were any substantial differences however. Both look identical and the colour of the actual unit as well as the aesthetics actually suit the Atari 800.

 

I've spent ages tweaking my 1084S, right down to tweaking the focus on the flyback to perfection when replacing it (do not do this is you're not familiar with safety around HT transformers!). The resulting IQ is actually very impressive connected to a C64 using separately shielded chroma/luma.

 

When I get my 600XL, I admit I'll probably run a 17" Dell IPS LCD - But only because CRT's are simply becoming so rare now. A 1701/2 here is worth $500.00 easily no matter what the condition.

Edited March 20, 2021 by Mazzspeed

[leech]

12 minutes ago, Mazzspeed said:

I think there was a 1701 and a 1702, not too sure if there were any substantial differences however. Both look identical and the colour of the actual unit as well as the aesthetics actually suit the Atari 800.

 

I've spent ages tweaking my 1084S, right down to tweaking the focus on the flyback to perfection when replacing it (do not do this is you're not familiar with safety around HT transformers!). The resulting IQ is actually very impressive connected to a C64 using separately shielded chroma/luma.

 

When I get my 600XL, I admit I'll probably run a 17" Dell IPS LCD - But only because CRT's are simply becoming so rare now. A 1701/2 here is worth $500.00 easily no matter what the condition.

Yeah, I've been looking for 1702s... Really would like one to go with the 800.  Considering modding the 400 to have composite out, but probably won't (it is a tad fuzzy on my TV).

[+DrVenkman]

The one above is a 1702. Colors on mine are particularly vibrant but don’t read TOO much into the exact artifact shades in that photo. As you know, it’s really difficult to get a good photo of a CRT with a phone camera, and in this case I was trying to get screen and the FSII box in focus and visible. Here’s an example from a gr.8 kaleidoscope demo program on Action! Toolkit disk. 

 

 

EDIT: Crap, I just realized I don’t know if this was one of my 800’s or one of my 1200XL’s. The photo is from December 2019, which makes me THINK it’s my Incognito 800 but I can’t tell from the photo. Worse, this is my other Commodore monitor, a 1902. 

[+DrVenkman]

Okay thinking again about this today while I have the time, here’s the kaleidoscope program running on my Incognito 800. This machine has stock video: 

 

 

[+DrVenkman]

And while I’m at it, here’s the same program running on one of my 1200Xl’s. This machine has a UAV rev D in it. Very noticeable difference in the artifact colors!

 

[+mytek]

The UAVs have a trim pot for adjusting artifacting. Might be nice to try turning that with the kaleidoscope program running to see if you can match the 800 results.

 

[leech]

1 hour ago, mytek said:

The UAVs have a trim pot for adjusting artifacting. Might be nice to try turning that with the kaleidoscope program running to see if you can match the 800 results.

 

In theory I should be able to do the same on my Incognito, right?  (Not that I want to take it all apart again)

[+Stephen]

8 minutes ago, leech said:

In theory I should be able to do the same on my Incognito, right?  (Not that I want to take it all apart again)

No - the Incognito does not have any of the video circuitry on it.  If you installed a UAV into the 800, yes.  Or, if you are using one of the Super Colour Cards, which implemented the UAV circuitry, it also has the adjustment.

[+DrVenkman]

1 hour ago, mytek said:

The UAVs have a trim pot for adjusting artifacting. Might be nice to try turning that with the kaleidoscope program running to see if you can match the 800 results.

 

Here you go, Michael.  

 

 

[leech]

17 minutes ago, Stephen said:

No - the Incognito does not have any of the video circuitry on it.  If you installed a UAV into the 800, yes.  Or, if you are using one of the Super Colour Cards, which implemented the UAV circuitry, it also has the adjustment.

Yeah, sorry, my 800 does indeed have a SCCC in it.