Hooking an 800XL up to a TV via A/V

[liquidcross]

Currently, my XL's using the RF output to run to my TV. Is there any way I can get standard A/V (ie RCA) output of the system instead? Less interference that way...

[racer raul]

Look here...

http://www.howell1964.freeserve.co.uk/Atar...800XL_Video.htm

 

It requires that you make your own cable.

 

In my particular case, after I made the cable I got no color... only B&W... i had to open up the computer & connect 2 spots with a wire to get color... but can't find it to save my life right now...

 

At least I hope the link will get you going in the right direction.

[racer raul]

Also found this...

 

http://www.a8maestro.com/sites/mtgcat/prod...oda8/eh0101.htm

[deathtrappomegranate]

Monitor (DIN-to-phono) cables are often available on ebay.

 

It's the same cable as the C64.

[+Mitch]

Look here...  

http://www.howell1964.freeserve.co.uk/Atar...800XL_Video.htm

 

It requires that you make your own cable.

 

In my particular case, after I made the cable I got no color... only B&W... i had to open up the computer & connect 2 spots with a wire to get color... but can't find it to save my life right now...

 

At least I hope the link will get you going in the right direction.

 

Sounds like you connected it to the luminance pin instead of the composite pin. Then you probably ran a wire over to the croma or composite pin. It works but not the cleanest way of doing it.

 

Mitch

[liquidcross]

Monitor (DIN-to-phono) cables are often available on ebay.

 

It's the same cable as the C64.

I've seen those...will they work with a regular A/V input on a TV?

 

And thanks for the links, raul.

[racer raul]

 

Sounds like you connected it to the luminance pin instead of the composite pin. Then you probably ran a wire over to the croma or composite pin. It works but not the cleanest way of doing it.

 

Mitch

 

I couldn't tell you for sure... I can't find the link now... but the connections I made where on the bottom side of the motherboard if I remember correctly.

 

I will admit, the picture isn't perfect... but damn near perfect sure beats RF...

 

Below is a pic of the LCD TV I use with the 800xl...

[Bryan]

Atari left Chroma disconnected in the XL's for some reason. Here's my article on upgrading the 800XL's video:

 

http://www.atariage.com/forums/viewtopic.p...t=41580&start=0

 

-Bry

[deathtrappomegranate]

I've seen those...will they work with a regular A/V input on a TV?

 

Yes, they will.

 

You'll get a better picture that way than by using RF, however the type of video mod that Bryan suggests is even better, if a little more tricky.

[racer raul]

Atari left Chroma disconnected in the XL's for some reason. Here's my article on upgrading the 800XL's video:

 

http://www.atariage.com/forums/viewtopic.p...t=41580&start=0

 

  -Bry

 

Bry...

 

I took my 800xl apart & found that I have connected R97 & R64 (right side from the bottom) to the Chroma output on the DIN using what I believe is a 1uf TAntalum cap. The vertical lines are there but not as pronounced as when I tried R67 & R68 for the CHroma output.

[Bryan]

I took my 800xl apart & found that I have connected R97 & R64 (right side from the bottom) to the Chroma output on the DIN using what I believe is a 1uf TAntalum cap. The vertical lines are there but not as pronounced as when I tried R67 & R68 for the CHroma output.

 

...getting the schematics out...

 

Okay... what's happening is you're taking the signal before the final buffer stage (collector of Q4). The monitor places a 75 ohm path to ground here, which pulls the signal down quite a bit causing the chroma signal to be weak, which has the side effect of causing it to be less visible in the picture. Most TV's will compensate for weak color by providing enough gain to bring the colorburst up to a reference level.

 

In other words, it works but is waaaay out of NTSC spec and if you weren't using separate chroma/luma, the picture would degenerate due to the weak color signal.

 

Q5 is an emitter-follower buffer stage, and its emitter is the only place where the circuit has enough current to drive a monitor properly.

 

-Bry

[Osbo]

2 Video

5 Audio

3 Ground

 

 

3o

2o o4

1o o5

 

Looking from behin the D 5 pins connector (Radio Shak) The cable is the same for Commodore or TI-99.

img_1350_1_