Pong TV game - A Scratch build Scale project

[Etienne MacGyver]

The tv i have here only has the RF input, so the modulator needs to stay  
I would preffer composite video, but the tv unfortunately does not have that input.

changing the tv for a tft panel is not an option as you might expect, we need CRT in this !  

I did already opened the unit to hardwire the adapter to it, and it has indeed more air than cirquitry in there  

I was already planning to take it out of the case, so i guess it will be fine, but thanks anyway  

the scale will be 1:2 , so i think there is plenty of room for the board.

[level42]

No SCART input on it either ?

If we can find the schematics it should be possible to hack in a composite input !

[Etienne MacGyver]

Nope, its a real "portable" old black and white tv.

It has a battery compartment under it (which i am porbably going to abuse and bolt that to the plank)

For the rest it has a cigaret lighter plug and thats about it 

I need to see the model, the label is a Lenco.

on the other hand, the real pong also uses a standard tv, so i bet they used RF also for the signal.

how more authentic can we wish for 

[Arch]

Cool project, Etienne. I will be following this.
I had forgotten how fun a party game Pong really is until me and a couple of friends spent hours on it recently. Good stuff!

[level42]

No, Pong did not have an RF output, they hacked a Video (it's not composite because it's B/W) input in the TVs they used. Really, the picture would be unacceptable for commercial use doing the unneccesary video to RF and RF back to video conversions.

Lenco.....that will be a tough cookie to find schematics but if there is a IC used in it we might figure out what the Video input is by that IC number....

[Etienne MacGyver]

Never knew that, but it sounds indeed logical.

I dont know if i want to go through all that "trouble" while i got a working setup now..
After all, its not a commercial product 

I'll try to see what the model is when i am home later..

[Etienne MacGyver]

Its a Lenco T-9033

I looked again and there is a 3,5 mm Jack thats says "a/v" so it could be that that is the audio video input..

Only think i dont know is if it is a 3 or 4 pin jackplug that i need to plug in there..
oh well, its working now, so if i dont find it, nothing is lost 

[level42]

YEAAAAAHHHHH, you really should try it, it will give SO much better picture

Did you already fill this in to ask for the SERVICE manual ? : http://www.lenco.eu/index.php?option=com_chronocontact&chronoformname=2&lang=nl


Sigh, Lenco used to be a pretty good brand of record players.....now it's another Grundig or Akai, Chinese products with a "familiar" name slapped on it....so sad.

[level42]

Was thinking it will probably be 3 pin. One for GND, one for video, one for audio. You can simply try there's little chance of blowing something up

Hey, you have some of those hand-held TV games, these put out composite video. If you have one of those cables from RCA to 3.5 mm you can have a look if you get anything. I assume the beeps come from the game itself so you only need the video right ?

[Etienne MacGyver]

Yes, i only need video

I guess you are right, i can try it with a cable like you say.

I think it will not harm indeed

Next task will be to "find" the video output before the modulator of that pong console..

Going to try "spongebob" now on the TV 

[level42]

Spongebob in B/W

I think it's pretty easy to find where the video signal is, it will be going into the modulator. Some pics of the bare PCB may help. Else PRC may be able to give tips about that ?

[Etienne MacGyver]

Spongebob was without batteries   so the Namco 5 in 1 was my image and sound generator for this test  

Part one, trying to see if the "fingertest" can determine whichone is the audio and whichone is the video input..

http://youtu.be/8qa-PevNEzQ

And a final test after hooking up the game and start it up.

http://youtu.be/UcGlmCq3Zto

Time to take the pong unit apart...  

Also i have searched for pics of pong cabinets, and there are indeed 2 models..
I think i will use the "darthnuno-model" as that is easier to create..  

[PunkRockCaveman]

The AY-3-8500 uses seperate pins for each part of the playfield and the sync. there are four playfield/ball/score display pins and one sync that you can combine via diodes. here is the pinout of the chip:



I'm pretty sure they did exactly that in your console. Just follow the pins and you will find the combined signal before it goes into the rf-modulator

[level42]

Yeah-yeah-yeah 

[Etienne MacGyver]

Lets see, i think i got the tools to dismantle this thing  




But something is missing in that pic....  yes ofcouse, the pong console!




The bottom..




first glance of the guts after opening..




Nice !, a socketed AY-3-5800 (aka "pong in a chip")




The manufacuter thought "hey i need to connect that coax cable together", why not use the middle pin of the powerswitch for that  




The mainboard, solderside (yes i know bad pic....)




Switches for the settings still in place, will remove those later and hardwire them to the settings i want to use..
I maybe create a jumper section instead of those bulky switches..




The inside of the controllers also carry alot of electronics.... NOT  




I am a bit in doubt to use this board and hack it, i might as well take the chip out of its socket and use a schematic like this :



Is that basicly what you used Jorg ?

on the other hand, a nice hacked up original old cirquit board also has its charm...