Atari A/V mod update

[Longhorn Engineer]

Longhorn Engineer:

Any update on the VCS mod? I'd love to be able to go S-video on my 2600 and on the 5200 later on.

 

I have a test on Monday and I have a couple other projects that need to be finished before I pull the 2600's out. The other projects should be done by sometime next week.

[Longhorn Engineer]

PCB designs and schematic are done.

 

I still haven't seen if it fits inside a 2600 Jr yet but thats next. The files where made in Eagle. If you change the board in anyway make sure to repost the changes and why.

 

http://longhornengineer.com/images/2.0.brd

http://longhornengineer.com/images/2.0.sch

 

Sorry for the messy schematic but its more function then form

Edited August 3, 2008 by Longhorn Engineer

[Longhorn Engineer]

Yep another update. I am out of CD4050's so I have to wait a few days for those to come in so I can work on the 2600's but I have some comparison shots.

[A.J. Franzman]

Wow, your stock RF is horrible -- much worse than the typical console I get here. You should be able to get it to look better than that, for a fair comparison. Perhaps a replacement cable and/or switchbox (if you're using one), and a few tweaks to the adjustable chokes are needed. If you have a frequency meter, the FSM tells you what values to tune for.

[+batari]

Thanks for the files, as it forced me to upgrade Eagle to open them, and I found that Eagle 5 is so much nicer!

 

It looks great except for one little thing - you've got a surface mount component on the board, which makes it so I cannot actually build one of these.

 

I realize it's a very important component that is not available in a through-hole package, but it does beg the question: if you have one SMT device, you might as well make the whole board SMT and have them assembled, as most of us cannot actually solder SMT so it doesn't make much sense to sell a board that we can only make 95% complete. That is, unless you are a soldering wizard and will sell the boards with the SMT device already on.

[Frotz]

Thanks for the files, as it forced me to upgrade Eagle to open them, and I found that Eagle 5 is so much nicer!

 

It looks great except for one little thing - you've got a surface mount component on the board, which makes it so I cannot actually build one of these.

 

I realize it's a very important component that is not available in a through-hole package, but it does beg the question: if you have one SMT device, you might as well make the whole board SMT and have them assembled, as most of us cannot actually solder SMT so it doesn't make much sense to sell a board that we can only make 95% complete. That is, unless you are a soldering wizard and will sell the boards with the SMT device already on.

 

As SMTs go, a SOIC is by far one of the easiest to solder. Wipe off most of the solder from the iron and tack down a corner pin. Move the opposite corner pin into position and tack that down too. The rest of the pins should now be aligned. I can deal with a single SMT.

[Longhorn Engineer]

Wow, your stock RF is horrible -- much worse than the typical console I get here. You should be able to get it to look better than that, for a fair comparison. Perhaps a replacement cable and/or switchbox (if you're using one), and a few tweaks to the adjustable chokes are needed. If you have a frequency meter, the FSM tells you what values to tune for.

 

I just took the Atari I was modding and plugged it into the TV with one of the adapters. Granted it is a LCD which typically exaggerate any imperfection in the signals. If I still had the Ataris I would adjust them but they are shipped off to there respectful owners. On the 2600 comparison I will send you a PM for help in adjusting the signal.

 

Thanks for the files, as it forced me to upgrade Eagle to open them, and I found that Eagle 5 is so much nicer!

 

It looks great except for one little thing - you've got a surface mount component on the board, which makes it so I cannot actually build one of these.

 

I realize it's a very important component that is not available in a through-hole package, but it does beg the question: if you have one SMT device, you might as well make the whole board SMT and have them assembled, as most of us cannot actually solder SMT so it doesn't make much sense to sell a board that we can only make 95% complete. That is, unless you are a soldering wizard and will sell the boards with the SMT device already on.

 

The SMT chip is a SOIC-8 which isn't that bad to solder. Making the entire board SMT would be a lot worse for me and you to solder. I could offer to have that one chip presoldered on as it only takes a minute to do.

 

I still have to clean up the boards silk screen as it would be very hard to read all that mess.

[SoundGammon]

Hi,

Somewhere in my collection of diagrams and such, I have a photo copy of the Atari 400/800 systems. Anyway, on the chroma/luminance, s-video, output, there is a 400pf cap from the luminance to the chroma line. I wonder if this cap "balances" the output. Thought you might like to try it. When I pick one up I'm going to try it on my 7800 and hope to get rid of that ghost or double image on the star background in Galaga and that double-dot look on Ms-PacMan.

[Frotz]

I still have to clean up the boards silk screen as it would be very hard to read all that mess.

 

It's not clear to me what's going on at R6 and R11. Are those ranges of values? Perhaps trimmers should go there?

 

Are you sure that C9 should be unpolarized?

Edited August 5, 2008 by Frotz

[+batari]

The SMT chip is a SOIC-8 which isn't that bad to solder. Making the entire board SMT would be a lot worse for me and you to solder. I could offer to have that one chip presoldered on as it only takes a minute to do.

 

I still have to clean up the boards silk screen as it would be very hard to read all that mess.

Speak for yourself I can't solder surface mount reliably, not even SOIC, and believe me, I've tried.

 

As for all SMT, that would imply that you'd order boards and have them professionally assembled. In sufficient quantity, it won't be that expensive, and it may make up the difference since the overall component cost would be less and it will allow for a smaller board (with greater chance of fitting in a Jr.)

 

If you go ahead with the single SMT chip, I'd opt for getting a board with that chip already on there, as I'd probably screw it up.

[Frotz]

Just for fun, here's a layout I did from Longhorn's schematics. The board is a bit smaller than his and could be a bit smaller still if the resistors are mounted vertically. Is there enough vertical clearance in a Jr to do that?

[Longhorn Engineer]

The SMT chip is a SOIC-8 which isn't that bad to solder. Making the entire board SMT would be a lot worse for me and you to solder. I could offer to have that one chip presoldered on as it only takes a minute to do.

 

I still have to clean up the boards silk screen as it would be very hard to read all that mess.

Speak for yourself I can't solder surface mount reliably, not even SOIC, and believe me, I've tried.

 

As for all SMT, that would imply that you'd order boards and have them professionally assembled. In sufficient quantity, it won't be that expensive, and it may make up the difference since the overall component cost would be less and it will allow for a smaller board (with greater chance of fitting in a Jr.)

 

If you go ahead with the single SMT chip, I'd opt for getting a board with that chip already on there, as I'd probably screw it up.

 

The thing is I don't think they will be enough volume to move 50 of these units to make that profitable or hell break even anytime soon with this method. Remember I am a college student and can't invest in large capital.

 

 

Just for fun, here's a layout I did from Longhorn's schematics. The board is a bit smaller than his and could be a bit smaller still if the resistors are mounted vertically. Is there enough vertical clearance in a Jr to do that?

 

Well the 220uF caps will be taller then the resistors.

[mimo]

Well, if you can make it work on a PAL 7800 then I need 2, if it can work on an Atari 400 I will want another 2, and one to replace my hatebitdomain NTSC 7800 mod, so 5 for me please

[Longhorn Engineer]

Well, if you can make it work on a PAL 7800 then I need 2, if it can work on an Atari 400 I will want another 2, and one to replace my hatebitdomain NTSC 7800 mod, so 5 for me please

 

Ok mimo. Don't worry your board is going up through the pile!

[Frotz]

Here's Longhorn's circuit with the resistors mounted vertically. The resulting board is 2 inches by 1.5 inches. That should be small enough to tuck into a Jr.

[BigO]

The thing is I don't think they will be enough volume to move 50 of these units to make that profitable or hell break even anytime soon with this method. Remember I am a college student and can't invest in large capital.

 

What's your threshold for "large capital"? If you have actually checked into it, what were the quotes like?

That's something I need to do for a project of about the same complexity, but haven't finalized enough of the design to be able to get prices yet..

[Longhorn Engineer]

The thing is I don't think they will be enough volume to move 50 of these units to make that profitable or hell break even anytime soon with this method. Remember I am a college student and can't invest in large capital.

 

What's your threshold for "large capital"? If you have actually checked into it, what were the quotes like?

That's something I need to do for a project of about the same complexity, but haven't finalized enough of the design to be able to get prices yet..

 

I haven't checked but my threshold is about $200-$300 (low i know but thats like 3-4 weeks of good eating and drinking!!)

 

I would rather keep the board through hole (except that one SMT chip) just for ease of putting together. I am going to offer the boards as bare boards and populated boards along with other methods.

 

Also I dont want to have to mess with some Chinese factory putting together some boards that don't work due to shoddy Quality control.

Edited August 7, 2008 by Longhorn Engineer

[BigO]

The thing is I don't think they will be enough volume to move 50 of these units to make that profitable or hell break even anytime soon with this method. Remember I am a college student and can't invest in large capital.

 

What's your threshold for "large capital"? If you have actually checked into it, what were the quotes like?

That's something I need to do for a project of about the same complexity, but haven't finalized enough of the design to be able to get prices yet..

 

I haven't checked but my threshold is about $200-$300 (low i know but thats like 3-4 weeks of good eating and drinking!!)

 

I would rather keep the board through hole (except that one SMT chip) just for ease of putting together. I am going to offer the boards as bare boards and populated boards along with other methods.

 

Also I dont want to have to mess with some Chinese factory putting together some boards that don't work due to shoddy Quality control.

 

No, I don't suppose $300 will buy much in that arena. If that was all that was needed, I could cash in some aluminum cans for ya. Ah, college days. I miss the learning, but I don't miss only being able to afford one meal per day.

 

I hear ya on the China thing. Chinese quality control seems like it's all done by the end user.

 

I agree that keeping as much as possible through-hole would make it more friendly for the average electronics hobbyist. I can solder SOIC, but it gets on my nerves fairly quickly.

[Longhorn Engineer]

No, I don't suppose $300 will buy much in that arena. If that was all that was needed, I could cash in some aluminum cans for ya. Ah, college days. I miss the learning, but I don't miss only being able to afford one meal per day.

 

I hear ya on the China thing. Chinese quality control seems like it's all done by the end user.

 

I agree that keeping as much as possible through-hole would make it more friendly for the average electronics hobbyist. I can solder SOIC, but it gets on my nerves fairly quickly.

 

Well I think the mod will be offered 4 ways. Ordered in escalating prices.

 

1. Free Schematic and PCB design (online of course)

 

2. Bare PCB with component bag (SOIC soldered to board) (possibly through AA?)

 

3. Completed PCB (possibly through AA?)

 

4. Installation in Atari

 

Should give everyone what they want

[BigO]

No, I don't suppose $300 will buy much in that arena. If that was all that was needed, I could cash in some aluminum cans for ya. Ah, college days. I miss the learning, but I don't miss only being able to afford one meal per day.

 

I hear ya on the China thing. Chinese quality control seems like it's all done by the end user.

 

I agree that keeping as much as possible through-hole would make it more friendly for the average electronics hobbyist. I can solder SOIC, but it gets on my nerves fairly quickly.

 

[...]

Should give everyone what they want

 

So, it'll be free then?

[Longhorn Engineer]

No, I don't suppose $300 will buy much in that arena. If that was all that was needed, I could cash in some aluminum cans for ya. Ah, college days. I miss the learning, but I don't miss only being able to afford one meal per day.

 

I hear ya on the China thing. Chinese quality control seems like it's all done by the end user.

 

I agree that keeping as much as possible through-hole would make it more friendly for the average electronics hobbyist. I can solder SOIC, but it gets on my nerves fairly quickly.

 

[...]

Should give everyone what they want

 

So, it'll be free then?

 

you wish. don't know the final cost till I get the pcbs made.

[Artlover]

PCB designs and schematic are done.

 

I still haven't seen if it fits inside a 2600 Jr yet but thats next. The files where made in Eagle. If you change the board in anyway make sure to repost the changes and why.

 

http://longhornengineer.com/images/2.0.brd

http://longhornengineer.com/images/2.0.sch

 

Sorry for the messy schematic but its more function then form

Ok, I'm a bit confused.

 

Is this a universal a/v mod designed to work on all system, or are these schematics only for the 2600 version and you haven't posted the info for the 7800 & 5200 ones?

[Longhorn Engineer]

PCB designs and schematic are done.

 

I still haven't seen if it fits inside a 2600 Jr yet but thats next. The files where made in Eagle. If you change the board in anyway make sure to repost the changes and why.

 

http://longhornengineer.com/images/2.0.brd

http://longhornengineer.com/images/2.0.sch

 

Sorry for the messy schematic but its more function then form

Ok, I'm a bit confused.

 

Is this a universal a/v mod designed to work on all system, or are these schematics only for the 2600 version and you haven't posted the info for the 7800 & 5200 ones?

 

Universal. I havent tested the 2600 all the way yet. So expect V2.1 soon.

[Frotz]

In my talks with Longhorn about circuit design, I identified three resistors that IMHO would be better replaced with pots. Two of them are to deal with differences between the 2600, 5200, and 7800. The remaining one needs to be very precise. Longhorn says that this would put people off having to do such adjustments. I say that if someone's keen enough to install one of these things, that someone should be just fine with adjusting some pots, particularly if the instructions are "set it to the middle and wiggle it around until the picture looks right". Opinions?

[Longhorn Engineer]

In my talks with Longhorn about circuit design, I identified three resistors that IMHO would be better replaced with pots. Two of them are to deal with differences between the 2600, 5200, and 7800. The remaining one needs to be very precise. Longhorn says that this would put people off having to do such adjustments. I say that if someone's keen enough to install one of these things, that someone should be just fine with adjusting some pots, particularly if the instructions are "set it to the middle and wiggle it around until the picture looks right". Opinions?

 

I guess we should leave it up to the people buying these things. I only go with resistors cause its cheaper on my end. But an extra $.75 for pots won't hurt.