7800 AV Mod: Anyone now do it?

[Lynxpro]

Atari should have made a 7800 II that had AV out built in in 1988 or 1989.

 

And a POKEY. And an AMY. And 4-joystick ports with Gauntlet. And dust doors covering the cartridge port. And the 7800 ProLine Joystick Couplers. And cartridge boards that supported 1MB RAM/ROM like CPUWiz's modern VersaBoards. And ports of every single arcade game made by Atari Games.

 

And Elevator Action. And Impossible Mission NTSC that wasn't impossible to beat. And Skyfox!

[7800]

Just got my 7800 back from Electronic Sentimentalities... Glad to finally play my 7800 with s-video resolution. FYI... Joe will install the ports on the REAR of the unit if you request it.

[Zonie]

Seconded! I love mine. Note this part from the site:

 

http://electronicsentimentalities.com/InstallationServices.html

 

 

 

I like that part.

Ahh... Now I know why I have this problem... Why is this not on the electronic sentimentalities website? No mention of a switch for the TIA in the troubleshooting or installation instructions. No schematics. Nothing.

Time to go and take it all apart and put in the switch... I hate doing things twice.

Edited September 16, 2015 by Zonie

[phoenixdownita]

I have an LHE board and I have to say it really depends on the TV.

I have 2 LCDs, on one it looks like the colors are shifted (like if the blue is too soon and bleeds to the left of the picture) both on Comp and SVideo, via HDMI thru a XRGB Mini the SVideo signal is very acceptable [a little shift would help there too but not as bad], direct SVideo on a second TV is a no go (can't really sync for more than 5 secs although it looks nice for those 4.5 secs, so HDMI via XRGB Mini is the only way and looks very decent, still little shift).

 

Composite out to a very old 14" CRT looks instead much better .... and it doesn't need much adjustment for the color compensation, browns are not greenish ... whatever ... the 7800 it's one of the most finicky console if you ask me. I tried to do myself a composite and an SVideo mod but because I only used the TV that doesn't like SVideo I ended up purchasing LHE board thinking I did something wrong, although a little better is not that much better than what I had ... at least it's way more ordered and it didn't set me back a lot.

 

The TIA 9 switch clears some interference on the blacks (like rolling inclined bars) but that's it.

Edited September 16, 2015 by phoenixdownita

[Zonie]

Well, I put in a switch and took a closer look at the wiring and noticed I was off one pin on the Maria outputs. You remove two resistors, but connect to one that is still there and the first empty one, not both empty's. It works now. The website's instructions could use some cleaning up. Now I can play my 7800 on my 60".

Edited September 16, 2015 by Zonie

[adamchevy]

I have purchased an install from electronic sentimentalities for my 7800. But I haven't heard back in a couple days. Does anyone have Joe's shipping address?

Edited October 23, 2015 by adamchevy

[+-^CrossBow^-]

I have the LHE installed on my 7800. I installed it myself. But on my LCD going through a cheap composite/s-video to HDMI upscaler it doesn't look that great on either composite or s-video as there is quite a bit of bleed to the right of the sprites and some details missing. For instance on Dark Chambers through s-video I can only see the speckled dots of the floor when standing still. When you move they just disappear. Does the same with the composite though not quite as much.

 

Odd thing I noticed is that if I actually plug in both the composite and s-video into the upscaler at the same time, and switch to composite, then it actually looks better?!

 

However, when I later tested my s-video only to an actual crt with s-video on it the picture looked fantastic! So it really is dependent on the TV and equipment being used.

 

As for jailbars that appear, nearly all of my s-video modded consoles produce a jailbars effect. After using different TVs since, it is more a result of how the signal is being interpreted through the TV rather than an issue with the actual AV mods. The jailbars don't happen on every TV I've connected my consoles to.

[adamchevy]

I have purchased an install from electronic sentimentalities for my 7800. But I haven't heard back in a couple days. Does anyone have Joe's shipping address?

I love replying to myself. No worries Joe got back with me . Thanks for the help. No problem!

[killersquirel]

I want to and will get one of my 7800 modded from electronic sentimentalities, but I have heard a couple of mentions about an RGB mod for the 7800. Does anyone have any information about this?

[edladdin]

Today I got my modded 2600 and 7800 consoles back from Joe.

 

I'm so thrilled with the work he did. Previously both consoles delivered up all kinds of weird artifacts and problems, the 2600 to the point of being unplayable. This was making me especially sad, as its my original light sixer from 1981. Now everything looks crystal clear and razor sharp on both consoles. SO fantastic on my 52" Sony LCD teevee!

 

I also had problems with specific games. For example, with either an original cart or the Harmony cart ROM of Megamania the enemy bombs were totally invisible, rendering the game unplayable. Now with both versions everything is visible and I am back in action.

 

I am hoping I can talk him into making the same magic on my 5200. In the meantime, I can offer a hearty and unreserved endorsement for Joe's services.

[adamchevy]

Today I got my modded 2600 and 7800 consoles back from Joe.

 

I'm so thrilled with the work he did. Previously both consoles delivered up all kinds of weird artifacts and problems, the 2600 to the point of being unplayable. This was making me especially sad, as its my original light sixer from 1981. Now everything looks crystal clear and razor sharp on both consoles. SO fantastic on my 52" Sony LCD teevee!

 

I also had problems with specific games. For example, with either an original cart or the Harmony cart ROM of Megamania the enemy bombs were totally invisible, rendering the game unplayable. Now with both versions everything is visible and I am back in action.

 

I am hoping I can talk him into making the same magic on my 5200. In the meantime, I can offer a hearty and unreserved endorsement for Joe's services.

I had exactly the same experience with my 7800 that I just got back. Everything was awesome!

[Andromeda Stardust]

I'm still using my Best AV 780 on a regular basis. No complaints. It's just sad they do not appear to offer 7800 consoles through the site anymore. Maybe the supply dried up?

[oracle_jedi]

Well, I put in a switch and took a closer look at the wiring and noticed I was off one pin on the Maria outputs. You remove two resistors, but connect to one that is still there and the first empty one, not both empty's. It works now. The website's instructions could use some cleaning up. Now I can play my 7800 on my 60".

 

Definitely agree with you on the instructions needing some clean-up!

 

The mistake you made with could easily have been avoided if the instructions showed taking those signals from the solder pads directly next to pin 36 of U1. This also avoids having to try to solder a wire onto a resistor leg that is still in position. Instead you have two empty holes to solder into. Much simpler.

 

It is also worth mentioning that you can tap pin 5 of U11 from a point under the IC. I removed U11 to solder into that tap point but you could also access it from underneath the board.

 

Not mentioning the TIA switch is a serious omission. I took out the RF2/3 switch on my first install, as I figured that was a good place to mount the SVideo plug. I ran the audio line through the RCA jack of what used to be the modulator. I had to use a whole cutting drill bit to enlarge the RF switch opening to accommodate the SVideo plug, but cosmetically it looked great - almost factory issued.

 

The video output was good, but any 7800 game with a single color background, like Robotron (black), or Xevious title screen (green) I got the faint diagonal lines which are damn annoying.

 

Having learned about the TIA interference I then had to put the RF2/3 switch back in and re-purpose it to enable/disable the TIA. I pulled out component C3, which connects to the center pin of S7, and used the lower solder pad as a convenient place to run the TIA line from R22. I then used a Xacto knife to break the connection from the left pad of S7 to Q1, and soldered a line from the top of the left pad of S7 to the TIA input on the Longhorn. I also broke the ground line on the left pad, since I wasn't sure if that would affect the operation of the TIA when the switch was in the disable position.

 

So then I had to move the Svideo plug, and on the 7800 they're are not many places it can go. I decided to position it on the left side of the console as that seems common. The next problem is that the SVideo plug provided has the structural integrity of chilled butter. Even waiving a soldering iron in its direction makes it turn to black goo. And the Luma ground pin fell off when I tried to remount it.

 

I also made the mistake of not leaving enough clearance for the steel locking nut to go on. So I ended up having to enlarge the hole in the side of the case and using two locking nuts - one inside and one outside - to secure the SVideo plug. It looks like anyone else attempting this needs to mount the SVideo plug toward the back of the 7800 but leave at least 7.5mm of space from the center of the hole to the bottom of the case, and 1.5cm of space from the back of the case (viewed from the outside), to leave enough space to tighten the nut behind the plug inside the case. That doesn't leave much space for the audio and composite video lines, but there is just enough room in there.

 

The end result is a nice clean stable color image in both 2600 and 7800 modes, but the case now looks like a hack job, because it is.

 

I made mistakes on this one, and I need to own them, but some better thought out instructions would have gone along way to making this a simpler more enjoyable upgrade.