827 replies to this topic

[bcombee]

I got my kit in the mail today and it's already soldered up waiting to be installed one of my 2600s tonight. For the most part it was a smooth assembly. The surface mount chip wasn't too hard to get into place. I did find the two .1uf caps next to that chip to be a little problematic -- they were wider than the space on the board, and I'm afraid of a short between the legs. The resistors weren't too bad; I first installed all the 75ohms, then used a multimeter to get the values of the rest and stuffed them in the board. I really like that you have the resistor values silk-screened instead of R numbers; it was much easier to match things up. The only other footprint issue was the 7804; it took some delicate work to avoid solder bridges.

[bcombee]

OK, I got the mod installed in my 2600 Jr, but I get no video. I suspect that a lead came off the TIA. Lifting the leads wasn't too bad, but I had some difficulty soldering the wires to the chip and probably need to redo those connections. Getting everything to fit inside the case was also a bit tough, snd the sticky tape just doesn't work to hold the board in place while you're working.

I verified that there were no bridges and that I had continuity from the TIA pins to the 4050. I also read 5V between the buffer's VCC and GND pins. At this time, I think I may have pulled a bad 2600 Jr... I made the mistake of not testing the console first. The main reason I suspect this is that the sound also wasn't working, and that's a totally different part of the circuit.

Fortunately, I've got a few more Juniors, so I can pull a motherboard from one of them and reuse the case I already drilled. I'll be sure to verify the console works first before I start opening it up and soldering.

[Longhorn Engineer]

bcombee, on Tue Mar 3, 2009 10:22 AM, said:

OK, I got the mod installed in my 2600 Jr, but I get no video. I suspect that a lead came off the TIA. Lifting the leads wasn't too bad, but I had some difficulty soldering the wires to the chip and probably need to redo those connections. Getting everything to fit inside the case was also a bit tough, snd the sticky tape just doesn't work to hold the board in place while you're working.

I verified that there were no bridges and that I had continuity from the TIA pins to the 4050. I also read 5V between the buffer's VCC and GND pins. At this time, I think I may have pulled a bad 2600 Jr... I made the mistake of not testing the console first. The main reason I suspect this is that the sound also wasn't working, and that's a totally different part of the circuit.

Fortunately, I've got a few more Juniors, so I can pull a motherboard from one of them and reuse the case I already drilled. I'll be sure to verify the console works first before I start opening it up and soldering.

You have to press the foam tape pretty hard into the PCB for it to get a good contact with the board. Once its set it never lets go.

[bcombee]

Longhorn Engineer, on Tue Mar 3, 2009 11:28 AM, said:

You have to press the foam tape pretty hard into the PCB for it to get a good contact with the board. Once its set it never lets go.

It's actually on the Longhorn PC board pretty well -- it was the contact with tops of the other ICs that was problematic.

I ended up scavenging some parts from the 2600 board for other projects; you never know when switches, DB9 connectors, and a 2600 cart connector will be useful. Maybe I'll finally do a Flashback 2 conversion. I'm going to pull another Junior from my storage room tonight and try it out.

[Longhorn Engineer]

bcombee, on Wed Mar 4, 2009 11:13 AM, said:

Longhorn Engineer, on Tue Mar 3, 2009 11:28 AM, said:

You have to press the foam tape pretty hard into the PCB for it to get a good contact with the board. Once its set it never lets go.

It's actually on the Longhorn PC board pretty well -- it was the contact with tops of the other ICs that was problematic.

I ended up scavenging some parts from the 2600 board for other projects; you never know when switches, DB9 connectors, and a 2600 cart connector will be useful. Maybe I'll finally do a Flashback 2 conversion. I'm going to pull another Junior from my storage room tonight and try it out.

Did you try to reposition the board after you stuck it on? After it gets stuck I pretty much find it impossible to remove without ripping the foam. I wonder if the top of the chip was dirty or something. Might have to add "cleaning top of IC" to the guide.

Keep us updated bcombee.

[tremoloman2006]

I don't know if anyone needs the mod for a Sears Video Arcade II, but I figured I'd post a few pictures while I had mine apart today in case you need it LE.

Attached Thumbnails

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[bcombee]

Success! Then failure.

I got everything soldered onto Junior #2. While opened up, I verified that S-Video and sound were working, and the picture looked quite nice. Then, while trying to get the board positioned, pin 9 of the TIA which I'd desoldered and lifted broke off the package, leaving me just a little thin strip of metal to try to connect. Grrr! The wires going to the TIA are pretty stiff.

One thing that helped -- I opened the images from Longhorn's guide up in their own pages and used Firefox's zoom to make them larger. The default size on the guide page is a little small for me to easily follow.

I'm going to try to get it reconnected, but so far my attempts have come loose almost immediately, so I may have to try some alternative method, like adding a second wire and then soldering to that. If I can't get this going, I guess I'll have to try console #3

[bcombee]

OK, a few more minutes of fiddling, and I think I've got an OK joint for now. However, I'm going to try to find my 4-switch or 6-switch and move the mod to there. No only does it have more room inside, it really would look nicer too to have all the ports on the back. However, I still get video out after putting the case back on, so I'm counting this a success.

[Longhorn Engineer]

bcombee, on Wed Mar 4, 2009 10:14 PM, said:

Success! Then failure.

I got everything soldered onto Junior #2. While opened up, I verified that S-Video and sound were working, and the picture looked quite nice. Then, while trying to get the board positioned, pin 9 of the TIA which I'd desoldered and lifted broke off the package, leaving me just a little thin strip of metal to try to connect. Grrr! The wires going to the TIA are pretty stiff.

One thing that helped -- I opened the images from Longhorn's guide up in their own pages and used Firefox's zoom to make them larger. The default size on the guide page is a little small for me to easily follow.

I'm going to try to get it reconnected, but so far my attempts have come loose almost immediately, so I may have to try some alternative method, like adding a second wire and then soldering to that. If I can't get this going, I guess I'll have to try console #3

Unfortunately there is no easy way to attach the mod into non socketed Ataris like the Junior other then removing the entire TIA chip with a soldering iron which is considerably much harder then lifting a pin. Cutting traces is an option but it is risky and allot more dangerous. Lifting the legs should be fairly easy. I have had no trouble with broken legs but I have been doing this for awhile so I guess its practice.

Quote

I don't know if anyone needs the mod for a Sears Video Arcade II, but I figured I'd post a few pictures while I had mine apart today in case you need it LE.

I have never seen the insides of a Sears Video Arcade II. Looks like its socketed so it would be fairly easy and no lifted pins.

Oh and before I forget. Assembled mods are shipping Friday.

Edited by Longhorn Engineer, Wed Mar 4, 2009 11:45 PM.

[Longhorn Engineer]

bcombee, on Wed Mar 4, 2009 10:29 PM, said:

OK, a few more minutes of fiddling, and I think I've got an OK joint for now. However, I'm going to try to find my 4-switch or 6-switch and move the mod to there. No only does it have more room inside, it really would look nicer too to have all the ports on the back. However, I still get video out after putting the case back on, so I'm counting this a success.

Cool! If you don't mind when you finish can you post pictures of the install and images of the TV screen?

[bcombee]

Longhorn Engineer, on Thu Mar 5, 2009 12:46 AM, said:

Cool! If you don't mind when you finish can you post pictures of the install and images of the TV screen?

Here's the console


Here are close-ups of the jacks



Here are some screen shots:








The only oddness I've noticed is that the TV's video processor doesn't love double line kernels and will offset the second scanline some. However, the picture is still far nicer than I've ever seen a 2600 do. The colors look more subdued here; I'm not sure why, but it's likely just my screen's adjustment, since I like to have more of a film-like look. It may also be a weak joint with the color pin on the TIA, but I'd expect that to be more intermittent.

I'd show the interior, but I'm not planning on opening this one up until I move the mod to another console.

[Longhorn Engineer]

bcombee, on Thu Mar 5, 2009 10:02 AM, said:

The only oddness I've noticed is that the TV's video processor doesn't love double line kernels and will offset the second scanline some. However, the picture is still far nicer than I've ever seen a 2600 do. The colors look more subdued here; I'm not sure why, but it's likely just my screen's adjustment, since I like to have more of a film-like look. It may also be a weak joint with the color pin on the TIA, but I'd expect that to be more intermittent.

I'd show the interior, but I'm not planning on opening this one up until I move the mod to another console.

Looks good bcombee .

I would try tweaking your brightness/color settings there. I tried to balance the mod so it would look could on all Tvs. I doubt its a weak joint. My CRT displayed the image the best on the "warm" setting and my LCD displayed it the best on "Default".

If people could post about there issues/problems/stories on installing the mod it would be great. Would help iron out problems in the install method and the kit.

//So Far

1.Larger pinouts for install guides.

Edited by Longhorn Engineer, Thu Mar 5, 2009 10:37 AM.

[Vectorman0]

I will most likely be doing this mod on a Video Arcade II at some point. I'm still waiting for my boards to arrive, and I have some other systems to modify first. I really hope the boards get here today!

[bcombee]

I'd also add a quick guide to soldering to pins. I've done a lot of through-hole soldering and some surface mount, but getting a good bond to a chip pin requires a few different techniques. What worked best for me was to tin the wire with extra solder, then hold the wire to the pin and apply heat to wire while pressing it against the pin. I had some problems initially with the stranded wire getting frayed when I was trying to work like I normally solder, where I apply solder to the joint after it's had a moment to heat.

I'd also include tips on using a multimeter to check for continuity to make sure there's no solder bridges between the pins. I ended up with one that I found before powering up my device that I was able to fix, but if I'd not done the check, I might have messed up the circuit.

[Vectorman0]

I got my boards in the mail yesterday and put one together last night. I had to mount the resistors vertically, since the ones I have are too large to sit flush with the PCB - hopefully it will still fit inside the shielding. I hope to install it tonight. Once I have it done, I will be sure to share my results.

[Longhorn Engineer]

Vectorman0, on Fri Mar 6, 2009 8:45 AM, said:

I got my boards in the mail yesterday and put one together last night. I had to mount the resistors vertically, since the ones I have are too large to sit flush with the PCB - hopefully it will still fit inside the shielding. I hope to install it tonight. Once I have it done, I will be sure to share my results.

It should still fit. The caps are higher.

[NinjaWarrior]

Could you do a RGB Mod??

[Ian Primus]

NinjaWarrior, on Fri Mar 6, 2009 2:48 PM, said:

Could you do a RGB Mod??

This wouldn't be possible without adding a substantial amount of extra stuff to the poor Atari. The TIA generates the chroma and luma signals directly. Video does not exist as independent color signals anywhere in the console.

-Ian

[Longhorn Engineer]

Ian Primus, on Fri Mar 6, 2009 2:26 PM, said:

NinjaWarrior, on Fri Mar 6, 2009 2:48 PM, said:

Could you do a RGB Mod??

This wouldn't be possible without adding a substantial amount of extra stuff to the poor Atari. The TIA generates the chroma and luma signals directly. Video does not exist as independent color signals anywhere in the console.

-Ian

Well A simple Decoder is all thats needed really. The SECAM version of the 7800 does this already.

[Ian Primus]

Longhorn Engineer, on Fri Mar 6, 2009 3:39 PM, said:

Well A simple Decoder is all thats needed really. The SECAM version of the 7800 does this already.

True - but my point was that you'd have to add active circuitry to convert the chroma/luma levels to RGB - thus defeating the purpose of RGB - the video isn't going to get any _better_ by converting it after it's been generated.

-Ian

[Carpenter]

Ian Primus, on Fri Mar 6, 2009 5:45 PM, said:

Longhorn Engineer, on Fri Mar 6, 2009 3:39 PM, said:

Well A simple Decoder is all thats needed really. The SECAM version of the 7800 does this already.

True - but my point was that you'd have to add active circuitry to convert the chroma/luma levels to RGB - thus defeating the purpose of RGB - the video isn't going to get any _better_ by converting it after it's been generated.

-Ian

Definitely! That's why we're interested in Longhorn's A/V mod. The act of modulating and demodulating the video signal is no longer necessary in the actual TV sets because A/V inputs are now a de facto standard and this process introduces unacceptable noise in the signal. Generating a RGB signal wouldn't improve noise ratio by any means. This mod is the best we cand do for the Atari 2600.

I'm still waiting for my mod to arrive but I think it'll take longer to reach me here in southern Brazil. Congrats again!

[Mitch]

Longhorn Engineer, on Fri Mar 6, 2009 12:39 PM, said:

Ian Primus, on Fri Mar 6, 2009 2:26 PM, said:

NinjaWarrior, on Fri Mar 6, 2009 2:48 PM, said:

Could you do a RGB Mod??

This wouldn't be possible without adding a substantial amount of extra stuff to the poor Atari. The TIA generates the chroma and luma signals directly. Video does not exist as independent color signals anywhere in the console.

-Ian

Well A simple Decoder is all thats needed really. The SECAM version of the 7800 does this already.

SCART, but let that pass.

Mitch

[Longhorn Engineer]

Mitch, on Fri Mar 6, 2009 5:39 PM, said:

Longhorn Engineer, on Fri Mar 6, 2009 12:39 PM, said:

Ian Primus, on Fri Mar 6, 2009 2:26 PM, said:

NinjaWarrior, on Fri Mar 6, 2009 2:48 PM, said:

Could you do a RGB Mod??

This wouldn't be possible without adding a substantial amount of extra stuff to the poor Atari. The TIA generates the chroma and luma signals directly. Video does not exist as independent color signals anywhere in the console.

-Ian

Well A simple Decoder is all thats needed really. The SECAM version of the 7800 does this already.

SCART, but let that pass.

Mitch

opps Mitch is right. Typo on my part

Ok all the assmebled mods are packaged. Didn't make it to the post office before 5 so I will mail them tomorrow.

On Monday I will be opening up orders again for mods. There will be a 7800 prototype Mod at MGC so if you come by the BenHeck table you can ooh and ahh at it (no you can't buy it ).

Edited by Longhorn Engineer, Fri Mar 6, 2009 6:49 PM.

[Vectorman0]

On these 2.2D pcb's, is the hole for "L" (audio) for R, and vice versa? I saw you mention them being reversed, but in the guides, the "L" hole is connected to the Left audio jack.

[Longhorn Engineer]

Vectorman0, on Fri Mar 6, 2009 7:54 PM, said:

On these 2.2D pcb's, is the hole for "L" (audio) for R, and vice versa? I saw you mention them being reversed, but in the guides, the "L" hole is connected to the Left audio jack.

On 2.2D they are backwards. If you install the wires just like this



It will be correct for the guides.