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Composite mod Coleco Telstar

RevEng

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#1 tsunoni OFFLINE  

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Posted Fri Apr 1, 2016 6:52 PM

http://atariage.com/...r/23476-reveng/

 

This post is basically directed at RevEng because he stated he modified the Coleco Telstar to produce composite output: http://atariage.com/...e/#entry2469505

 

I have the exact same issue as him and I seek the solution of Composite video output! 

 

Please help a fellow ninja!

 

=I am brand new here=



#2 slydc OFFLINE  

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Posted Sat Apr 2, 2016 10:48 PM

Hi tsunoni,

 

First, what is your Coleco Telstar model ? I have A/V modded some few Dedicated Pong consoles as well as other Dedicated consoles.

The last one i've A/V modded was yesterday a Philips Las Vegas ES 2208. You can see a few of them on my Youtube channel but i'm

not showing how to mod them, just posted videos to hear and see what they really look like.

 

Anyhow, about half of the Telstar has a AY-3-8500-1 and it is very easy to mod for A/V (Audio/Video) output and the best is that you

won't need any electronic components (like resistors, transistors, etc...), just a few wires (and a iron solder). And if you can, open up

your Telstar and take a picture of the rear of the board (where all the solders are) so i can assist you step by step.

 

Until next time! =)

 

--- Sly DC ---


Edited by slydc, Sat Apr 2, 2016 10:48 PM.


#3 tsunoni OFFLINE  

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Posted Wed Apr 13, 2016 12:34 PM

The picture comes through but its very fuzzy but I can see the pong games running and I can play it but it is way too difficult to make out to want to play it. The screen is shakey and it produces a static fuzzy sound also on the tv set. the sound the comes from the console itself is fine. I dont want to spend too much money because I know I could buy another with $30. I can solder and aI modified my Atari 7800 for composite out successfully so I feel pretty good on that front.

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#4 slydc OFFLINE  

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Posted Wed Apr 13, 2016 1:33 PM

Ok, you have a model 6040. It's hard to read which type of TTLs you have but i'm guessing that they are CD4072

as many manufacturer used this TTL as a video summer. Anyhow, just take the following pins from the AY-3-8500-1:

#6 (ball output) + #9 (right player output) + #10 (left player output) + #24 (score & field output) and #16 (sync output)

and tie them all together and this makes your composite video output.

 

As for the sound, solder a wire to #3 (sound output) and this will be your Sound output. DO NOT solder a wire to one of

the terminal of the speaker or at the emitter of the transistor as this gives a amplified sound (either the sound will be too

loud or it will be too low).

 

Try this and you should be able to play on any monitor/tv with a A/V input as a GI AY-3-8500-1 (or the PAL version:

AY-3-8500 and even the Texas Instruments clones: TMS1955NL and TMS1965NL) doesn't need any op-amp circuit to

amplify the signal "IF" the signal are taken directly from the selected pins mentioned above.

 

Give me news on this when you can and have fun modding! =)

 

 

--- Sly DC ---


Edited by slydc, Wed Apr 13, 2016 1:36 PM.


#5 tsunoni OFFLINE  

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Posted Wed Apr 13, 2016 3:41 PM

Thanks so much!

The top chip in the picture is cd4011ae RCA605 and the bottom one is cd4072be RCA614. I dont know how to count the numbers on the ay-3-8500-1 chip. can you circle them in my image? or highlight them? do i just pull the chip out with needle nose pliers and bend those pins out and solder wires to them and combine those wires? 

 

Thanks again!

-Stephen P.


Edited by tsunoni, Wed Apr 13, 2016 3:42 PM.


#6 tsunoni OFFLINE  

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Posted Wed Apr 13, 2016 4:04 PM

"do i just pull the chip out with needle nose pliers" 

I just removed the board and looked under the chip in question and  noticed those pins are soldered so I guess I could just solder wires to those points then right? and do i count 1, 2, 3, 4, from the upper left of the chip, in the position, in the picture to the right, from top to bottom?



#7 slydc OFFLINE  

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Posted Wed Apr 13, 2016 10:58 PM

Hi again tsunoni,

 

You could remove the chip and bend the pins but if you apply to much force, you'll break the chip.

But if pins #6-9-10-24 + #16 are soldered on the back of the board then you can solder a wire on each

solder point and then tie (or solder) them together.

 

For the CD4072, generally all four video outputs are connected to this TTL but solder those four together

will do the same job. The CD4011 is for the 2MHz clock.

 

Here's a quick drawing (done in 2 minutes) to show how to connect the pins and how they are numbered:

 

8500.png

 

The pink arrow shows how to find pin #1. On any chip, there is always a small dented circle so this indicated pin #1.

Pin #2 is the ground but you can find other ground solder links on the back of the board.

Pin #3 is the sound output and pin #6+9+10+24 are the video output and pin #16 is the sync, so add all five

together to get a composite video.

 

There is also a schematic which should be quite close of the Coleco Telstar 6040:

 

201262422104249.jpg

 

If you had a Coleco Telstar Alpha (model 6030), all four video outputs are soldered together, so i just

soldered a wire from pin #16 to the four and output it with an A/V cable, like in this picture:

 

ct-alpha.jpg

(Look Ma! No electronic components for doing a A/V output! LOL!!!)

 

The result of this mod (gameplays) can be seen here on Youtube:

 

 

 

 

 

So keep me informed of the progress, until next time! :)

 

--- Sly DC ---


Edited by slydc, Wed Apr 13, 2016 11:14 PM.


#8 tsunoni OFFLINE  

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Posted Thu Apr 14, 2016 3:34 PM

Wow, yer tha bombb diggityyyy!! what do i do with the ground? 

thanks so much sly!


Edited by tsunoni, Thu Apr 14, 2016 3:35 PM.


#9 tsunoni OFFLINE  

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Posted Thu Apr 14, 2016 5:50 PM

This is where I am. I soldered, only, the composite points you labeled as yellow to this wire and wrapped it around this rca plug and powered it up while connected to my yellow rca input, on the flat screen but no signal was detected. I triple checked to confirm that the yellow ones are soldered to the right points.

Am using a wrong cable cord? Do I need to connect the ground to something? 

edit: I added another picture with the yellow cable I stripped to cross with the soldered wire that was combined with the 5 yellow wire points.. still nothin. a tthis point I hope i only need to connect a ground or something. 

Attached Thumbnails

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Edited by tsunoni, Thu Apr 14, 2016 6:30 PM.


#10 PhileasJWhoopie OFFLINE  

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Posted Mon Apr 18, 2016 4:15 PM

Thanks for this thread.  My Coleco Telstar is a Marksman, and a different chip.  I also have an APF TV Fun unit, and Unisonic Tournament 2000, and they might have this chipset, or just go out and get a different Telstar for this.  It would be nice to have one pong system with AV out.



#11 slydc OFFLINE  

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Posted Wed Apr 20, 2016 12:57 PM

@tsunoni:

 

Sorry for the delay, OK now back to business: You used "un-isolated" copper wires ? YIKES! Don't use that! Use isolated wires like in this picture:

cablecolors.jpg

 

I use simple A/V cable like those ones:

 

30eb898cd2f0b2e8ba63b64d2cfa80ac.jpg

 

With an isolated wire, there is two wires inside: one that is isolated (like the colored ones) and the other that

is not isolated (the copper one). The copper one needs to be grounded and the other cables (the yellow one)

needs to be soldered with the composite video output (the 5 pins together) and the white or red (or both) needs

to be soldered to the pin #3 (sound output) and the copper again soldered to the ground.

 

vid00.png

 

and the isolated cables needs to be stripped like that:

cable00.jpg

 

When using copper wires like you did, this makes a LOT of trouble as any not-isolated cable can touch any solder point and make

a connection causing a problem or another and also radio frequencies can do statics.

 

Try this and let me know the result. Until next step! :)

 

 

@PhileasJWhoopie: The Coleco Telstar Maksman uses a AY-3-8512-1 (16-pins chip) and i haven't tried to A/V mod one yet.

As for your APF TV Fun, i would need the model to tell which chip is inside it and for the Unisonic Tournament 2000, that one

uses a AY-3-8500-1 and is VERY EASY to A/V mod it. If i remember correctly, it has 4 in/out pins which are: +5 volts, ground,

video and audio on a side of the RF modulator.

 

I would need a picture of the RF modulator to tell you which pins is what as it was my very first A/V mod i did about ten years ago.

 

 

--- Sly DC ---



#12 tsunoni OFFLINE  

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Posted Thu Apr 21, 2016 7:55 PM

It works! It's great except the right paddle isn't showing up at all. I dont know if I broke it somewhere along the way. Also, I started bridging connections on the chip while it was on to try and see if the right paddle would appear and it reset it a few times and shut it off a few times. After that everytime i turned it on the picture would start normal then glitch and then the sound and picture would make glitchy sounds and then it turned off completely. it wasnt doing that at all before i tried bridging pins on that chip. I think I really did it in, in some odd way.

 

Anyways before I went and messed everything up this is what I did differently:

    I cut the long cable to be shorter and stripped a composite (yellow) video cable an twisted the, already soldered, wires to the yellow. I then soldered the yellow cords ground to the chips ground (point 2) and viola! [no right paddle though picture was flawless and it didnt glitch out and die after 20 seconds]

 

Again though, I don't know what I did to make the right paddle completely disappear! 

 

Thanks for everything! If you have any idea how to display the right paddle, please, of course, let me know.

SO COOL! No more rf at all! 100% clear!

 

ps did i mess it up with bridging random pins on the chip with a screw driver (usually pins right next to one another)?? 



#13 tsunoni OFFLINE  

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Posted Tue May 10, 2016 5:34 PM

So I plugged it in an hour ago and it worked perfectly, except no ball was showing and I think the score was stuck at 15 for both left and right. I removed the board from its clip-ins and it completely stopped working so I put it back and it was working the same way it was as I originally stated in this post. I then removed the board from its clip-ins and it stopped working again so I put it back again but this time it hasnt worked since. Ooppss, that wasn't as bad as what I was about to do though. I then pulled out the main chip and two of the pins were bent. I didnt know if it was because they were meant to be or I did it because the exact two pins werent used for anything on the board (they didnt lead to anything), I then broke off their legs accidently and tried putting the chip back on and it wouldnt go in. I could only get one side but not the other. 

 

I removed the main chip just to see if I could. I think I will have to get an other one entirely (pong console) because I really did a number here. 

 

Thanks for the help. I will probably get the same one and do the same mod but successfully instead of, well, unsuccessfully. 

 

Thanks everyone for everything



#14 tsunoni OFFLINE  

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Posted Mon May 23, 2016 6:31 PM

HUGE CHANGE OF EVENTS: IT WORKS! SEE HERE: 

 

I was testing a few Entex handhelds that I bought from eBay. They were made in the early 80's and they used the same size batteries as my Telstar pong console. Long story short the batteries were messing with EVERYTHING on my Telstar pong console. I put in normal C batteries and Boom, it worked even with the horrendous chip reinstall.

 

I completed the audio mod and by stripping the two audio rca wires (red and white), twisted them together for the solder to pin #3. I twisted their grounds together and rapped it around, and together with, the other ground wire connected at pin #2.

 

C battery adapters that didnt work with anything c batt adapter.jpg

 

aa rechargable inside the C batt adapter that didnt work aa.jpg

 

Bad chip reinstall: fucky--chip-install.jpg

 

Complete board and thanks for everything truly!! board--complete.jpg

Attached Thumbnails

  • fucky--chip-install.jpg
  • board--complete.jpg
  • c batt adapter.jpg

Edited by tsunoni, Mon May 23, 2016 6:34 PM.


#15 slydc OFFLINE  

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Posted Tue May 31, 2016 6:27 PM

Hi tsunoni!

 

Sorry for the long delay to getting back at you. I'm seeing and reading that you finally finished your A/V modding of your Coleco Telstar,

that's great! Even if you had problems, you didn't gave up and that is a great quality. =)

 

Batteries are not really recommended as when they are beginning to be drained, the voltage is too low and gives problems like distorted

or snowy picture, etc. Always better with AC adaptors, in your case you need a 9 Volts/200 to 500milliAmps with positive tip.

 

So i'm tipping my hat to your effort and your perseverance! =)

 

-- Sly "forgot your name" DC --- (lol!)


Edited by slydc, Tue May 31, 2016 6:27 PM.


#16 swlovinist OFFLINE  

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Posted Wed Jun 15, 2016 10:55 AM

I would love to have a modded Telstar at the Cowlitz Gamers for Kids show this next year.  For that fact, a modded pong in general would really be cool.  If anyone can help out, please let me know. 



#17 slydc OFFLINE  

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Posted Fri Jun 17, 2016 8:10 PM

Hi swlovinist,

 

I would be glad to mod one for you at no charge but the problem is that i live in Canada and shipping a console is now at least $25

and another $25 to ship it back so this is not recommended. Which Telstar model you have ? Or if you want to mod another Pong

console, which is it ?

 

I have modded a couple of Pong consoles, dedicated consoles and game systems like Atari 2600, Colecovision, RCA Studio II, etc.

Most of the videos on my Youtube channel comes from game consoles/systems i've modded myself. It would be my pleasure if i can help

out in any way. =)

 

--- Sly DC ---



#18 swlovinist OFFLINE  

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Posted Sat Jun 18, 2016 12:57 AM

Hi swlovinist,

 

I would be glad to mod one for you at no charge but the problem is that i live in Canada and shipping a console is now at least $25

and another $25 to ship it back so this is not recommended. Which Telstar model you have ? Or if you want to mod another Pong

console, which is it ?

 

I have modded a couple of Pong consoles, dedicated consoles and game systems like Atari 2600, Colecovision, RCA Studio II, etc.

Most of the videos on my Youtube channel comes from game consoles/systems i've modded myself. It would be my pleasure if i can help

out in any way. =)

 

--- Sly DC ---

 

Thanks for the offer.  Tsunoni has offered the service to me and Cowltiz Gamers thanks him.  I also will be bringing this pong unit to a classroom in the Spring.  



#19 slydc OFFLINE  

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Posted Sat Jun 18, 2016 9:00 AM

No problem at all, glad to read that tsunoni has offered you to mod your Pong console. =)

 

--- Sly DC ---



#20 Kain3n OFFLINE  

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Posted Sat Jan 14, 2017 8:54 PM

hello, new to this forum. i have the same Telstar and was looking do do this mod as the picture was super fuzzy and adjusting the rf box did nothing. i had found another post somewhere else in this forum about doing this mod but it did not look super easy and no extra parts like this method. i actually ordered the extra parts off Ebay to do it but one part never actually showed up so was looking to see what the part was and found this post. i am going to try to mod it this way as it looks way easier! but was wondering if there's any added benefit to doing it the other way? here are the schematics from the other forum post i found it

 post-23476-0-04916800-1329682515.gifpost-23476-0-49315700-1329684215.gif



#21 slydc OFFLINE  

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Posted Thu Jan 19, 2017 12:21 PM

Thanks for this thread.  My Coleco Telstar is a Marksman, and a different chip.  I also have an APF TV Fun unit, and Unisonic Tournament 2000, and they might have this chipset, or just go out and get a different Telstar for this.  It would be nice to have one pong system with AV out.

 

OUPS!!!

 

Sorry mate! I completely passed-by on your comment.

 

The Coleco Telstar Marksman uses a "AY-3-8512-1" (same as for the Sears Telegames Gunslinger II) and this chip has only 16-pins. This one can be done with an A/V output but the video signal is inverted, so you need to re-invert it with a simple 2N3904 or 2N2222.

 

Before trying to mod your APF TV-Fun, which model is it ? As APF uses different chips depending on their models. And for the Unisonic Tournament 2000, this one uses a AY-3-8500-1 as this one was my very first Pong console i've A/V mod about 15 years ago. :)

 

--- Sly DC ---



#22 slydc OFFLINE  

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Posted Thu Jan 19, 2017 12:45 PM

@Kain3n: Hey! a fellow Canuck! :)

 

A strait answer: Nope! But... in some Pong consoles (other than Coleco ones), i did use a similar circuit to boost the composite video signal

(a 10k resistor from the base of the transistor to the ground, a 1K resistor from the emitter to the ground and sometimes a 75 ohms resistor

one end between the emitter & 1k junction and the other end to output the video signal - BTW, the transistor is a 2N3904 or 2N2222) and the

collector is attached to the Vcc (between 5V to 12V DC).

 

So basically for some Pong consoles, i just use either 3 or4 components (a 10K resistor, a 1K resistor and a 2N3904 or 2N2222 transistor and

sometimes a 75 ohms resistor)..that's it!

 

The 7805 isn't needed at all as any 2N3904 or 2N2222 can take a voltage between 0 to 12v easely and the 100uF capacitor, only use if you

get some static noises on the screen. I even A/V modded my 6-switch woodgrain Atari 2600 with only 3resistors and a transistor and the

video signal is great.

 

But you can do the A/V mod circuit that you attached to your post, this also works but it's uses more parts.

 

BTW to anyone, if you have a Pong console which as either a Texas Instruments TMS1955 or TMS1965, these are EXACT copies of the

AY-3-8500 & AY-3-8500-1. AY-3-8500 & TMS1955 are PAL chips and AY-3-8500-1 & TMS1965 are NTSC chips.

 

Give us news on your modding progress! :)

 

--- Sly DC ---


Edited by slydc, Thu Jan 19, 2017 12:47 PM.


#23 Kain3n OFFLINE  

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Posted Thu Jan 19, 2017 5:22 PM

hey and thanks slydc! :) the 2N3904 was the one part of all the parts i ordered that for some reason never showed up lol. So I  have completed the mod your way with zero parts and it is working great! I actually pulled this Telstar out of my friends neighbors trash can 17 years ago but had limited soldering ability and circuitry knowledge then so it sat in a dark corner of my parents basement until I found it again a couple months ago when i was visiting them and digging around to retrieve my old Colecovision which i may also try a composite mod on soon ( I just finished cleaning the power switch to fix the garbled video, and replacing the SN74LS541N so that controller #1 would work so it too is working again). so for the first time in 17 years that i've had this Telstar.... it' ALIVE! mwahahahahaha. I wanted it to still look and feel as authentic as possible so i only did the video and not the sound and reused the existing RF cable for the video. here is pics of what i did, i just bridged 3 pins on the bottom right instead of coming off 3 different places on the 8500 chip. and followed the traces to easier solder points for the rest. and then un-soldered the RF connector port from the pcb attached everything to it and the glue gunned it to the back of the casing. I did not have the connector glue gunned to the casing yet in the picture.

telstar.JPG telstar2.JPG telstar3.JPG the ball in the 3rd picture is moving too fast for my crappy phone to get a clear shot of but it's all crystal clear and working perfectly!  :)


Edited by Kain3n, Thu Jan 19, 2017 5:43 PM.


#24 Kain3n OFFLINE  

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Posted Thu Jan 19, 2017 5:39 PM

I also have one more pong unit I would like to try this mod on. It's a Radio Shack TV scoreboard. I just opened it up and it uses the same AY-3-8500-1 chip so I am assuming i can use this same zero extra components method?  If not i will have to re-order one of those transistors that never came last time lol. the RF cable connector is external on this so I will have to decide if I want to drill some holes and mount composite cable jacks on the case or drill one small hole for a permanently attached cable before proceeding. here is a stock photo of the unit, it's a neat one with a couple extra options than the Telstar with pull out wired controllers.

tvscoreboard.jpg



#25 Kain3n OFFLINE  

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Posted Thu Jan 19, 2017 10:37 PM

well i tried modding it the same way as the coleco telstar and it just does not work. came out like this 

tv scoreboard.JPG guess i will have to get ahold of a transistor :)







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