(Insert stupid Blog name here)

The audio output pad uses a standard size that comes in the KiCad footprint library actually. But I'm confused on the via spacing comment? They are spaced to match up with the resistors you solder it down onto. The other vias on the top are aligned with the vias on the UAV and those I can't control of course.

 

Odd about the audio the way it was but yeah, I told you before in PMs that the audio had been done in stereo as I could tell from the old mod that was in place. But didn't know they removed the trace completely as that wasn't needed. Glad you sorted it out and got it corrected though. What's up with Tower Toppler though? Unless that is through a Concerto? I don't think TT is working through the Concerto yet is it?

 

Oh..to answer about your color bars question.

 

So..first off with the UAV at least, those bars won't actually match when the rest of the colors are set correctly. You will always have the right bar seem more olive or brown vs the left side. It is the same way with the color bar generator for the 2600. If you do properly match them as you stated, the other colors will look a bit off. So for 2600 games I eyeball the color using Pitfall. But on the 7800 side, what I do is wait for the console to have been on for about 5min and then adjust so that the bars are close but always with a bit more brown/olive on the right side bar vs the left.

 

Through RF output, it is a different story and you actually do want those to match up. In fact, I usually use the RF for that purpose and then leave it. The UAV will alter some of the tints on the colors and that is just how it is. Again, it was initially designed for the Atari 8-bit computer line and its palette of colors as a result. Changes were made to it so that it could be used on the 2600 and 7800 but there is some tradeoff in the process with color accuracy as a result. 90% of the time it is where it need to be though.

 

And now I realized you are using a concerto. That 7800 utility actually tests the POKEY too during the audio test. But ONLY if it detects the Pokey. However, as Fred didn't include the RNG on the HOKEY (Which I'm assuming you are using?), it doesn't see the Pokey chip and as a result you are only getting the TIA audio channels on that test. With an actual Pokey installed, it will play the two TIA channels, and then 4 more channels showing Pokey Audio channel 1 - 4. On mine Concerto, that pokey test is absent with my HOKEY. However, with a HOKEY in my old Mateos cart it does work, but doesn't display while playing the tones, they just play on their own.

 

And...there are some unused vias you can use on the board to test continuity of the connections to the UAV. They are all pretty easy to get to minus the points for Sync and Lum 1 which are covered with components on the board. But the rest of them can be checked in other places. Remind me and I can send you an old diagram I have as I used to wire the UAVs to those alternate points vs along the resistors a few years back.

 

 

23 minutes ago, -^CrossBow^- said:

But I'm confused on the via spacing comment? They are spaced to match up with the resistors you solder it down onto. The other vias on the top are aligned with the vias on the UAV and those I can't control of course.

Sorry - I should've been clearer: The UAV jumper vias are what I had the most trouble working with. Bad close-up vision + ham-fisted soldering skillz aren't a great combination for soldering things that are right next to each other.

23 minutes ago, -^CrossBow^- said:

What's up with Tower Toppler though? Unless that is through a Concerto? I don't think TT is working through the Concerto yet is it?

It's through the Concerto. There's a hacked ROM that works with some consoles. It runs on my 7800, but not John's. I'm hoping the next Concerto firmware update addresses it, but there's no final release version of it yet - just interim builds.

5 hours ago, -^CrossBow^- said:

Through RF output, it is a different story and you actually do want those to match up. In fact, I usually use the RF for that purpose and then leave it.

Sadly, not an option with this 7800.  

5 hours ago, -^CrossBow^- said:

The UAV will alter some of the tints on the colors and that is just how it is. Again, it was initially designed for the Atari 8-bit computer line and its palette of colors as a result. Changes were made to it so that it could be used on the 2600 and 7800 but there is some tradeoff in the process with color accuracy as a result. 90% of the time it is where it need to be though.

90% for any NTSC device is probably 20% better than normal.     

5 hours ago, -^CrossBow^- said:

And now I realized you are using a concerto. That 7800 utility actually tests the POKEY too during the audio test. But ONLY if it detects the Pokey. However, as Fred didn't include the RNG on the HOKEY (Which I'm assuming you are using?), it doesn't see the Pokey chip and as a result you are only getting the TIA audio channels on that test. With an actual Pokey installed, it will play the two TIA channels, and then 4 more channels showing Pokey Audio channel 1 - 4. On mine Concerto, that pokey test is absent with my HOKEY. However, with a HOKEY in my old Mateos cart it does work, but doesn't display while playing the tones, they just play on their own.

I'm using an actual POKEY. RevEng mentioned in the comments there that the issue (in this case) is the header in the ROM file for the Utility Cart needs to be updated, which will be included in Trebor's next ROM pack update.

5 hours ago, -^CrossBow^- said:

And...there are some unused vias you can use on the board to test continuity of the connections to the UAV. They are all pretty easy to get to minus the points for Sync and Lum 1 which are covered with components on the board. But the rest of them can be checked in other places. Remind me and I can send you an old diagram I have as I used to wire the UAVs to those alternate points vs along the resistors a few years back.

Cool - thanks! When I get to my 7800, I'll give you a nudge about it.

 

Thanks again for all the help in getting this particular one working again - especially for the Mount/Audio/Chroma board. That really simplified the process a great deal. (And thanks to alex_79 as well!)

 

I'll be modding a couple of 2600's as well, so I'll be able to do a comparison of what it's like to install UAV's in those systems. 

For composite & S-Video color (hue) is determined by the phase of the chroma signal versus the colorburst signal in the horizontal sync at each specific point in time.  On the 2600 & 7800 the way they selected the phase for each pixel is taps off a delay line.  So color 0 is the first tap on the line (no delay, matches colorburst) while color 15 is the last tap on the line.  The "length" of the delay line is set by the resistor (to compensate for slight differences at the gate level).  So if you want to have consistent colors for all 2600s the easiest way is to adjust the resistor so color 0 is the same as color 15.  You lose a color, but it's a quick & easy way to do the job.  OTOH, if you want all 16 colors then you can adjust the resistor so the two are different (which is what most emulators effectively do I believe).

 

Oh, don't forget that the 7800 has separate resistors for the 2600 TIA and 7800 MARIA.

Edited January 19, 2023 by EricBall

3 hours ago, EricBall said:

For composite & S-Video color (hue) is determined by the phase of the chroma signal versus the colorburst signal in the horizontal sync at each specific point in time.  On the 2600 & 7800 the way they selected the phase for each pixel is taps off a delay line.  So color 0 is the first tap on the line (no delay, matches colorburst) while color 15 is the last tap on the line.  The "length" of the delay line is set by the resistor (to compensate for slight differences at the gate level).  So if you want to have consistent colors for all 2600s the easiest way is to adjust the resistor so color 0 is the same as color 15.  You lose a color, but it's a quick & easy way to do the job.  OTOH, if you want all 16 colors then you can adjust the resistor so the two are different (which is what most emulators effectively do I believe).

Thanks for writing that up! I remember hearing how color was generated on the Stella at 20 tapes, but couldn't recall exactly where they said it (or what the exact explanation was).

3 hours ago, EricBall said:

Oh, don't forget that the 7800 has separate resistors for the 2600 TIA and 7800 MARIA.

Yep. The 2600 colors look fine, the 7800 colors need to be tweaked a little.