827 replies to this topic

[FABombjoy]

Ransom, on Mon Apr 20, 2009 12:47 PM, said:

Pretty much anything that's a light or pastel color comes out very dim, no matter the game. And the problem persists whether the console is connected to an LCD or CRT TV.

I made 2 changes to mine that may fix this problem.

I just installed my first board tonight in a 4-switch & found things were too bright on s-video & composite. Color Bar Generator confirmed that the first 3 bars on the greyscale screen were the same intensity which kills off a lot of detail.

The fixes for s-video were:
Remove 75 ohm resistor that runs above the FMS6400
Increase resistance on 75 ohm to the right of FMS6400 to about 150ohms

I haven't messed with the composite side but I'll bet it's about the same.

Anyway, after these two changes, the s-video appears spot-on.

[Longhorn Engineer]

FABombjoy, on Tue Apr 21, 2009 7:49 PM, said:

Ransom, on Mon Apr 20, 2009 12:47 PM, said:

Pretty much anything that's a light or pastel color comes out very dim, no matter the game. And the problem persists whether the console is connected to an LCD or CRT TV.

I made 2 changes to mine that may fix this problem.

I just installed my first board tonight in a 4-switch & found things were too bright on s-video & composite. Color Bar Generator confirmed that the first 3 bars on the greyscale screen were the same intensity which kills off a lot of detail.

The fixes for s-video were:
Remove 75 ohm resistor that runs above the FMS6400
Increase resistance on 75 ohm to the right of FMS6400 to about 150ohms

I haven't messed with the composite side but I'll bet it's about the same.

Anyway, after these two changes, the s-video appears spot-on.

I will look into this. Thanks for the suggestion.

[FABombjoy]

I'm wondering if ASEL on the FMS6400 should be low. Does luma really need the 6dB gain? How does it look without the above changes, but with ASEL tied low? I would think this would be ideal as the FMS chip runs hot; lowering the gain should cool it off a bit.

I should have some time tonight to do a few more experiments.

Edited by FABombjoy, Wed Apr 22, 2009 7:50 AM.

[cwilkson]

FABombjoy, on Wed Apr 22, 2009 6:49 AM, said:

I'm wondering if ASEL on the FMS6400 should be low. Does luma really need the 6dB gain? How does it look without the above changes, but with ASEL tied low? I would think this would be ideal as the FMS chip runs hot; lowering the gain should cool it off a bit.

I should have some time tonight to do a few more experiments.

Assuming 75 Ohm outputs, the output voltage gets divided by 2 when loaded by a standard 75 Ohm video input. That's why the 6dB option exists.

What's the peak-to-peak voltage on your FMS inputs Longhorn?

[Longhorn Engineer]

I have ran it low before and the image was way to dark.

Quote

What's the peak-to-peak voltage on your FMS inputs Longhorn?

I will have to check later when I get home.

Edited by Longhorn Engineer, Wed Apr 22, 2009 8:26 AM.

[Fangorn81]

Not trying to derail the conversation, but I still am not getting anything...I looked at Ben Heck's page, and it looked like he wired his up differently...I am going to take pics of my board when I get home and post them so everyone can see exactly what I am talking about.

Also, I am gonna take it to my friends house and try it on his TV, though if I can't get it to work with my TV, it will be a huge bummer.

[Fangorn81]

Ok, this is ungodly blurry, but all I have right now is my phone camera.



The Red is actually not attached at the moment, but had been on pin 20 of the TIA. And the pins connected Grey, White, Orange and Brown wires are bent up.

Edited by Fangorn81, Wed Apr 22, 2009 6:33 PM.

[Longhorn Engineer]

Fangorn81, on Wed Apr 22, 2009 6:32 PM, said:

Ok, this is ungodly blurry, but all I have right now is my phone camera.

Blurry_Mess.jpg

The Red is actually not attached at the moment, but had been on pin 20 of the TIA. And the pins connected Grey, White, Orange and Brown wires are bent up.

Looks like its attached correctly. When you those pins you dont need to cut the leads on the resistors. Make sure none of the wires are connected or bridged.

[Frotz]

Has anyone heard from Longhorn lately? I'm wondering when my modboards will arrive.

[Longhorn Engineer]

Sorry everyone last week of school.

[Vectorman0]

I tried to do this mod on a second 2600 last night and I have spent three hours trying to troubleshoot it. Audio works 100%, but there is no video (just a fast flicker when powering on). I tried two separate video mod boards, two TIA's, 2 s-video jacks, 2 separate 2600 motherboards. I tested the wires for continuity, and tested for bridged points. I tried on different TV's with different video cables too, and different power supplies. They system works fine without the mod installed using RF output. Maybe I messed up both mod boards, or I am blind and soldered a couple wires backwards? Any ideas or suggestions would be appreciated.

[Fangorn81]

That is the same problem I have had, and have found no solution so far!

[Prodos8]

I've read or been told not to remove the pins on the TIA chip from the motherboard to make the connections. Something to do with them being open-collector or something. YMMV.

[Longhorn Engineer]

Sorry about the lack of emails and updates fellas. I have 3 more finals to go. I will be done on Sunday.

[Ransom]

Longhorn Engineer, on Thu May 14, 2009 10:13 AM, said:

Sorry about the lack of emails and updates fellas. I have 3 more finals to go. I will be done on Sunday.

Good luck on 'em!

[tremoloman2006]

nm

Edited by tremoloman2006, Sun May 17, 2009 10:59 AM.

[Vectorman0]

Prodos8, on Wed May 13, 2009 2:31 AM, said:

I've read or been told not to remove the pins on the TIA chip from the motherboard to make the connections. Something to do with them being open-collector or something. YMMV.

This was the problem, thank you! I removed all of the wires from the TIA and did everything by this guide and it works.

[Longhorn Engineer]

Ok finals went fairly well. I am waiting on some PCBs to arrive. Should arrive here sometime next week. Then all orders placed will be filled. Sorry about the wait!

[Fangorn81]

I can't follow the guide because the board isn't the same?

[Longhorn Engineer]

Fangorn81, on Tue May 19, 2009 11:38 AM, said:

I can't follow the guide because the board isn't the same?

Hey Fangorn you can attach the PCB directly to the TIA legs. The PCB is labeled on which wire goes to which pin. Make sure all pins stay connected to the board except pins 6 and 9 (Blank and Color) and pins 12 and 13 (Sound). Those 4 pins have to be lifted. The only reason the guides show cutting resister leads is that is allot easier then cutting TIA leads.

If you have a multimeter you can find the resister pinout for yourself and email it to me so I can add it to the guide.

\

[pepax]

I can't wait to buy the PCB! However, it depends on the the PAL VCS compatibility report.

[Longhorn Engineer]

Ok all orders placed and paid for at this point have been filled. This includes all PCBs, Unassembled, Assembled and Modded Ataris. They will ship tomorrow (5/27/09) afternoon.

Will get to work ASAP on the PAL version. Very sorry to our brothers across the pond

[Longhorn Engineer]

All orders have been shipped.

[Longhorn Engineer]

Ok for all future orders please direct to this site.

http://www.longhorne...omods/Videomods

I have a paypal cart system setup.

[InactiveX]

Longhorn Engineer, on Wed May 27, 2009 5:04 AM, said:

Will get to work ASAP on the PAL version. Very sorry to our brothers across the pond

Very pleased to hear it! Am following the PAL progress with eager attention. Thanks LE!