Composite Video Mod AY-3-8610

[spacebiscuit]

Hi All,

 

I have a Binatone TV Master Mk10 Pong system, the chip used is a AY-3-8610.

 

I'm trying to add a composite video mod, I've bought the fairly common board:

 

https://www.pcbway.com/project/shareproject/Thumbnail_board_for_Atari_2600_7800_RF_composite_modification.html

 

I've found a few tutorials done on earlier models but haven't yet found anything on this specific model. I believe I need to find a a common point on the boards where the various video signals are combined with the sync. I believe the pinout for the chip is:

 

 

So for example pin 7 and 8 or the left and right player video signals. Using a multi-meter I was unable to trace a point on the board that is common for pins 2, 7 and 8.

 

Is anyone able to help me identify where I should be soldering to pick up the video signal. Here are some photos of the mainboard and the chip:

 

 

Looking at the image above, the array of 10 solder points on the left hand side are games switches so can likely be eliminated, and the rightside of the board are option switches and the power input, so I am fairly certain that what I am looking for is around by the main ship.

 

 

The manual also has this diagram for the board:

 

 

Any help would be much appreciated. Thanks!

 

Edited May 14, 2023 by spacebiscuit
update to images

[+KylJoy]

Is there an RF modulator in the unit somewhere?  You might be able to look at where the video is entering it and trace that back to its origin.

[spacebiscuit]

So I actually managed to get something working, using a multi-meter it was pretty straightforward to pick up 5-6v and a ground/negative.

 

Then using pure brute force I touched the video cable on various solder points I suspected could be handing the video, I picked up a video signal around the modulator and although it is acceptable it was a little wavey around the white court border areas.

 

I then found a better quality signal around a cluster of resistors which I think aligns with what I read about modding a different Binatone model. However, regardless of which point on the board I use to pick up the video, one of the player's bats/paddles appears as a black graphic (rather than white) on the screen. At first I thought it was entirely missing until you move over the court border and it's black colour is contrasted and becomes apparent. I suspect this is/was a fault with the console rather than being the result of the mod.

 

So this is what I am trying to fix, not sure if this could be related to the resistors - I'm kind of fumbling around in the dark so any input would be welcome.

 

Also something to note, initially I left the audio cable hanging loose, but if I touched it the quality of the video instantly improved. Seems it needs to be grounded otherwise it introduced interference.

 

 

 

[slydc]

Try this:

 

At first, put a probe just before the red X to see if the video signal is strong enough, if not then cut the circuit

where the red X is and put a transistor (2N2222 or 2N3904) and the collector goes to either 5 or 9 volts and with

two resistors (75 and 1,000 (1k) ohms) to amplify the video signal. That's it....have fun!

[spacebiscuit]

On 6/1/2023 at 3:43 AM, slydc said:

Try this: 

 

At first, put a probe just before the red X to see if the video signal is strong enough, if not then cut the circuit

where the red X is and put a transistor (2N2222 or 2N3904) and the collector goes to either 5 or 9 volts and with

two resistors (75 and 1,000 (1k) ohms) to amplify the video signal. That's it....have fun!

Thanks - is this a general suggestion to get the possible video or a fix for the "dark" paddle that I can barely see on the screen.

 

By the way, I found that the video was vastly improved with the mod's audio wire attached to the board. Previously I didn't have it connected, it was hanging lose and it was causing interference, likely it wasn't grounded?

Edited June 6, 2023 by spacebiscuit

[slydc]

Depends on the "strength" of the video signal. Some Pongs with the AY-3-8500-1 have a good video signal without using an amp and some other needs the video

signal to be amplified. I just recently modded an Bandai TV-Jack Add-On 5000 and didn't need any amp circuit (audio & video). For a 'dark' paddle issue, you'll need to amplify

the video signal so that the background (among the rest) will be less darker.

 

You can get the "Audio/Sound" directly from pin#13 of the AY-3-8610 because on the circuit of the Binatone, it is amplified with 9015C transistor so it can "drive" the speaker.

Because if you take the audio/sound from the speaker (or just after the collector of the 9015C, the audio will be very loud even at a very low setting on your TV/monitor.

For sounds for ANY dedicated Pong chips (GI, TI, MOS, Mitsubichi, NEC, etc) it is always better to get the audio from the audio output of the chip.

 

If your curious, i recently upload videos of all four cartridges of the Bandai TV-Jack Add-On 5000 on my Youtube channel and didn't use any amplifier for both audio & video signals.

[CatPix]

Or you can just leave the sound going to the speaker Perhaps adding a volume slider.

[spacebiscuit]

On 6/17/2023 at 9:09 PM, slydc said:

For a 'dark' paddle issue, you'll need to amplify

the video signal so that the background (among the rest) will be less darker.

 

Not sure if you missed it my original post but it is only one of the paddles which is dark, the other is fine. Presumably they are both the same shade of white, therefore my assumption was that something on the board related to the specific paddle output perhaps needs replacing?

 

Your solution would simply amplify the entire console video output wouldn't it?