Installing a UAV into a heavy sixer
The process to install the UAV into a heavy or light sixer is pretty well known and documented. In summary you basically set the jumpers on the UAV for the 2600 setup and then solder a socket ontop of the 4050 IC chip and header pins into the UAV and plug it into the socket. Job done...
However, there is a caveat to this method that doesn't become apparently until you find yourself moving consoles around a lot. And when I mean moving the consoles, I mean as in them being packed up, stacked up, put away into storage, shipped about...etc. Or let us say...for convention use. What happens is that all the jostling and movement of the console overtime will cause the UAV to walk about of the socket and come loose. Once this happens, the socket is essentially worn out and it will have more often. The solution is to direct wire solder in the UAV to alternate points and then affix the UAV in a way that isn't as likely to come loose over time.
The solution I came up with recently, was to use the empty space on the PCB where originally Atari had planned to install a built in game on the console. There is space and markings where a 4k ROM would have been installed on the sixer PCBs for this purpose that was never used. So that provides a nice flat area to attach the UAV with double adhesive tape or what I use which, is 3M Dual Lock fasteners. Basically plastic industrial grade velcro like reels that can hold up to 10LBs of weights supposedly before coming separated. More then enough for a little ole UAV. The adhesive that is used on the Dual Lock stuff is also crazy strong if you clean the surface well before hand. To attach to the UAV is trickier because the UAV doesn't have a smooth surface on it that is really large enough. This is due to the UAV having components installed on both sides of the PCB, plus the wiring etc that is also needed. To help get around this, I've been buying 3/4" shrink tubing that I can get very cheaply locally and sliding it over the UAV after my initial wiring to it is done to provide me with a much smoother and consistent surface area for the other dual lock velcro to attach to. This install required the use of the basic version of the UAV that doesn't require jumpers to be set as it is all direct wire.
The wiring on the sixer might not be consistent across the heavy and light as I only had this heavy on hand currently. But it turns out that 4 of the 5 connections needed for the UAV can actually be wired and soldered to empty unused vias on the main board. Even better, is that these alternate vias (I think they were test points), are very close to where the UAV sits and provides some pretty direct runs keeping everything nice and tidy. The pic below shows three unused vias right in a line above the disc capacitor marked as C210 on the board. From left to right these vias connect to TIA pins 2,7, and 8. If you look at C210, you will see an unused solder pad directly right of it. It is between the markings for C210 and R208. That is where you can tap audio from as it is directly connected to pins 12 & 13 off the TIA. You will see another unused via just off to the side of R214 below. That connects directly to TIA pin 5. Finally, you need a connection for the TIA color signal. That can be had easily from soldering a wire to the right leg of R212 as oriented in this picture below.
Now, something to keep in mind is that on these older 2600s and on later 4 switchers, (possibly the jrs?). Atari would add in an 800ish Ω resistor to help with color saturation. However, this resistor will cause the colors to look way off in most cases through the UAV and has to be removed from the circuit. It is located essentially between the pin 6 and 9 positions below the TIA chip on the main board at location R213. What I usually do is to just de-solder and lift the right leg of this resistor as that is also tied directly to pin 9 of the TIA. So you could use this solder pad for the color signal as well but it would require a longer wire to route down there.
Power and ground can be had from several places. I ended up using one of the unused vias for the non-existent 4k ROM for ground. Power was possible from here also, but would have been in the way of my UAV board installing nice so I took the +5v off the bottom leg of R207 just left of where I placed the UAV. Again these points were chosen to keep all wiring to short runs. Shorter wires help with minimizing signal loss and keeping the UAV board in place over time.
And that is pretty much it. I should also mention that if wire length isn't a concern, then with the exception of audio and the power and ground connections, all of the other points mentioned can also be tapped from the resistor legs mounted below the TIA. I don't recall which is which right now, but I know that all of the TIA connections can be had from them also. Just requires longer wires to route around the TIA to those resistors. It is also possible to mount the UAV on the bottom of the pcb using strong double adhesive tape and then just solder the wires directly to the legs of the TIA. But you would have to make sure you are using the basic version of the UAVs for such an install and it would require likely drilling a hole on the side of the RF housing box for your output wires to come through. You will see in the overview pic below of the UAV installed, that my output wires go under the cartridge slot and out the back. That is because the housing has some thin slot openings on the top and bottom allowing wiring to come through. It might require having to file the metal down a bit to opening the gap but might not require it depending on how the housing for the 2600 was done.
I might create an install video that essentially tries to cover UAV installs in the sixers and 4 switch units in the future as a single all in one video. While solder points are varied across the different revisions of the console, there is enough similarity that I think a single install video with pauses and different sections for the different revisions is possible. Have to think about that...
Edited by CrossBow