From what I’ve read in various sources, Atari Football was the first arcade game to use a track-ball. At least it was the first Atari video game to use one. (A side note — Atari Football uses the same trackball that was used in Missile Command so this article applies to you Missle Commanders, too.) On my Atari Football, when rolling the Player 1 track-ball, there were problems. Putting the game into test mode, player 1 could move horizontally left and right but vertical movement was a problem. Rolling the track-ball forward and backward would only move the player (“X”) in one direction (backward).

The track-ball works just like a “ball” computer mouse in the sense that it has an opto-encoder to determine the magnitude (speed) and direction of the ball. Two infrared emitter/detector pairs are mounted on a PCB (printed circuit board). A spoked wheel passes through a gap in between each emitter/detector pair. The spoked wheel is mounted to a roller shaft, which is turned by the track-ball when it is spun against the roller shaft. The emitter/detector pairs’ outputs are each amplified by a 2N3643 transistor. The pairs’ signals are then sent to the Atari Football CPU board. The CPU board can then compare the two signals from the emitter/detector pair to compute the speed and the direction (forward/backward) of the ball. The trackball in Football (as well as Missle Command) uses two of these opto-encoder PCBs in tandem with two roller shafts. One for the X (horizontal) direction and one for the Y (vertical) direction.

Since I could move the player in the horizontal direction, that particular opto-encoder PCB was fine. The vertical opto-encoder became my focus. First, I removed the track-ball and swapped the molex connectors for the horizontal and vertical opto-encoder PCBs. I then saw that the vertical direction now worked while the horizontal direction exhibited the same problem. That narrowed down the problem to the opto-encoder PCB, rather than a problem with the wiring harness or CPU main board. I removed the opto-encoder PCB and checked to see if the emitters were working. How can you do that with infrared LED emitters you might ask? Why, with a digital camera, as a CCD can detect infrared light! (See the above photo.) I held my digital camera up to the opto-encoder PCB and saw the emitting LEDs, plain as day.

Since the opto-encoder was telling the CPU that the trackball was rolling in one direction, rather than two, maybe the problem was with the infrared emitter/detector pair. Since both pairs are needed to compute movement in two directions, maybe one of the pairs was not working. I connected my oscilloscope to each of the two pairs and sure enough, the detector in one of the pairs was not working. I decided to replace the two 2N3643 transistors and the two 0.001uF ceramic disc capacitors in hopes that they might be causing the problems. (I substituted 2N2222A transistors [TO-92 package] for the 2N3643 transistors, by the way… it was all I had on hand and could be used as a substitute.) No change! So, I went to the Mouser website and ordered a few different “infrared interrupter” (aka “phototransistor optical interrupter switch”) items. I ordered a few to see which ones worked best.

I settled on the Fairchild QVE00118 phototransistor (Mouser # 512-QVE00118) as it had the right gap and pin dimensions. For each emitter, I had to replace the resistor that is between the +5V supply and the anode of the emitter, as the new emitter requires less voltage than the original emitter. So, I changed each of the two 150 Ohms (brown/green/brown) resistors to 270 Ohms (red/violet/brown in the picture below) to bring the voltage down to around 1.2V. That’s all the resistors I had to change. When you mount the QVE00118, it is labeled “E” for emitter and “D” for detector. It also has the positive “+” designations. Even though the Atari opto PCB (on the underside) has an “E” label — don’t let it fool you, it’s not the emitter but the detector side! It fooled me…

Atari Football is now fully working. What a great game! So much fun, especially to relive arcade football of the 1970s and 80s.

Parts List (Trackball Opto Board):
All parts can be ordered from Mouser
2 Transistors: 2N3643 (or 2N2222A) TO-92 Package
2 Ceramic Disc Capacitors: 0.001uF
2 Phototransistor Emitter/Detector: QVE00118
2 Resistors (one for the anode of each QVE00118 emitter): 270 Ohms, 1/4 Watt

Now that I had the Atari Football all cleaned up, it was time to install the Bob Roberts capacitor kit for a Wells Gardner V1000. Football has a huge 23″ black and white picture tube and I wanted to make sure those Xs and Os looked their best. The monitor can be removed in one of two ways. The monitor is bolted to a piece of plywood that can slide out of the cabinet. You just open the control panels, loosen some wingnuts, and the monitor and plywood monitor mount slides out. I opted for removing the glass and cardboard “stadium” bezel, then unbolting the monitor from the plywood mount and lifting the monitor out of the top. What a pain. I did this because I didn’t realize you could easily slide out the monitor from the side until later… That’s what I get for not bothering to read the manual.

Smoke

After the game had been powered on for 5 minutes, I noticed that smoke came up from the monitor and I smelled burning plastic. Great! (I am being sarcastic, of course.) I thought that I had done something wrong with my cap kit install. Fortunately, no. I let the game cool off, powered it on again, and slid out the motherboard to see if it might be the culprit. The mainboard and monitor are close together, so it could’ve been either one. Sure enough, the huge wirewound resistor that is near the edge connector was smoking. It had been dipped in some kind of black plastic hence the burning plastic smell. This particular resistor is part of the +5V regulator, so I decided to replace the regulator’s main components. Heck, since the Atari Football mainboard has two regulator circuits — one for +5V and another for +12V, I decided to just replace them both. The electrolytic capacitors in each regulator circuit needed to be replaced; after all they were 30 years old!

Another thing I noticed while the smoke was happening was the picture would jitter and I would hear a slight screeching noise (from the +5V regulator area!) at the same time. It looked like the +5V regulator was probably causing that, too. I ordered the following from Bob Roberts:

+5V Regulator Circuit
LM323 or LM323K (TO-3 Package) +5V Regulator — Don’t forget the mica insulators and thermal paste!
R37 – 4 Ohm, 10W Wirewound Resistor
C23 – 470uF 25V Axial Capacitor

+12V Regulator Circuit
LM7812CV – +12V Regulator
CR1, CR2 – 1N4001 Diode
C50 – 10uF 25V Axial Capacitor
C62 – 4700uF 25V Axial Capacitor

On my mainboard, the resistor that was smoking (R37) was actually a 20W resistor. The schematics call for a 10W resistor which I used. You could still use a 20W resistor — someone probably put it in there to make the circuit more robust to the current draw. In the photo above, you can see the new components that I installed for the +5V regulator circuit.

After “upgrading” the two regulator circuits with new parts, Atari Football was back in action after all these years! No more smoke, no more screen jitters, no more screeching.

I also replaced the 22/44 Molex edge connector for the wiring harness that connects to the mainboard. It was a pain to crimp because of many wires and small gauge wires. I will have to make another post on my advice for crimping.

LEDs

One of the red LEDs for selecting plays was not working. I replaced it and I noticed how dim the other LEDs were. Even in the dark they were hard to see against the lamps that illuminated the play diagrams. So, I changed out all the red 5mm LEDs which made a dramatic difference. (You can order the LEDs from Bob Roberts as well.) The play panel is very vibrant with the new lamps and LEDs.

Now that things were looking on the up-and-up, I tried playing a few games (yeah, I know — it’s a two player game…) The Player 1 track-ball was not working correctly. I could move the player in the horizontal direction but not the vertical direction. Next up, fixing the track-ball opto board.

Seeing the side art (below) reminds me of watching football games with my dad and uncles on Sundays… nothing like that 70s style…

I can only imagine how many Pabst Blue Ribbons and Rheingolds were accidentally knocked over and poured into Football’s trak-balls and offense/defense play charts. What makes me say this, you might ask? Well, my first tip off was the grime on the play charts as they were coated in some kind of yellowy film. Upon removing the monitor bezel, the back of the cardboard audience shroud had liquid stains. Once I opened the control panels and removed the trak-balls, I could see what these machines endured 25-30 years ago. Each trak-ball had a generous amount of black plastic chaff (from the trak-ball), hand grease, and beer residue on the bottom of the trak-ball harness. Fantastic! I broke out the Mean Green de-greaser and went to work.

Atari Football was the first (by most accounts I’ve read, anyway) trak-ball game produced. The game is made up of “X”s and “O”s, similar to a play chart in those old football movies. This game also has a few interesting highlights:

• A 23″ black and white monitor — huge by arcade standards where monitors were usually 19″
• Cocktail style cabinet where the players stand instead of sit (the base can be removed to the players can sit, but then again, you need every bit of room for the english you have to put on the trak-ball!
• Players don’t move the trackball as a precision device like in Centipede, Crystal Castles, and Marble Madness. Players must slam their hands on the trak-ball to roll it as fast as possible. This, of course, contributed to the memories of bruises, blood blisters, and pinched skin on players hands.

Cleaning Up

As I mentioned before, I began cleaning the game by removing the trak-balls and using Mean Green to clean them up. I had to take apart each trak-ball assembly so I could remove all the nastiness in there.

After cleaning, I lubricated all the bearings with teflon gel (also known as PTFE), which you can find at Radio Shack. I cleaned the trak-balls with Novus #2 plastic cleaner/polisher. After putting the trak-balls back in place, I cleaned the play charts with Novus #2 to make them look as good as new. I replaced the #44 bulbs with #47 bulbs which draw less current and are little less hot as to ensure the play chart plastics will last longer. For the carriage bolts that hold the trak-ball in place on the control panel, I used a $1.99 drill wire brush to get the rust off the bolt heads.

Ahhh, now the Atari Football cabinet is looking much better! Thank goodness noone rested their cigarettes on the plastic play display! If I saw that I would have to spike a big blue capacitor into the cardboard audience. Powering on the game, I hear the audience roaring and I see graphic garbage on the screen. Oh well — now it’s time to start troubleshooting the electronics!


Arcade Stats:
Manufacturer: Atari
Year Released: 1979
Cabinet Date of Manufacture: January 23, 1979
Cabinet: Stand-up Cocktail
Monitor: 23-inch Vertical Black and White Raster
Coin Counter: 8590
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