POLE POSITION – A RESTORATION – PART 11

Welcome back great people. Thank you for taking the time to once again return to read through the next update in this restoration. This is the update we have all been waiting for. Get your ten pence’s at the ready and “Prepare to Qualify”. With all the work undergone to get to this point, it is finally time to pair the PCB with the cabinet and flick the switch…..

Never mind the usual biscuit and brew count, we don’t have time for that, we have fun stuff to, erm, have fun with.

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Actually, wait, there is always time for tea and biscuits, so whilst you go and boil the kettle and chose between chocolate hobnob or coconut cream sandwich, I want to say a few poignant words about the arcade community.

It’s coming up for ten years since I bought my VERY FIRST CAB, having discovered a whole new online world, where those imposing arcade games that had had such a happy influence on my childhood, were actually being owned and played by ordinary people in their ordinary homes.

I was overwhelmed with the opportunity to acquire such cabinets and equally scared at the prospect of having to repair these ageing behemoths that I didn’t understand. But before any purchase was made I joined up and started to ask questions on online forums, such as the wonderful and still going strong, UKVAC. And it was within these online messages that I started to make some (online) friendships. Allies in the hobby, on hand with advice, quick to answer questions, whilst offering the support and help I needed as I took my first tentative steps into owning an actual cab.

Those friendships have only grown and carry on doing so. UKVAC continues to be at the forefront for many in the hobby; newcomers, seasoned owners and those that have turned the hobby into part of their lifestyle. Online friendships have matured into real life friends (IRL, the kids would say), and it is these close friends, buddies and brethren that I want to speak about, because without some, this restoration would never have happened at all, and without others, we would not be at this point.

Such is the warmth of the community. I’ve made friends from across the country and even the world, through this hobby. Some real close friends, who welcome me into their homes and games rooms. Who not only put up with me, but put me up in their homes. Some true Arcadians, who live the arcade dream and have turned this crazy hobby into part of their life AND work.

But back to this project, Pole Position, and without a cabinet, there would be no restoration. I had spoken to a buddy called Frazer, (who is even more besotted with this game than I am, and who had acquired a number of cabinets, through some diligent importing), about my love for the game and put out some tentative feelers. Frazer went on to speak to Martin, who on hearing about my yearning, contacted me, with an offer to buy his cabinet, and the restoration was on.

If you’ve followed this restoration from the start, you will know I’ve had some help, but not all help has been mentioned, so bear with me whilst I make amends. (I can almost guarantee I will still miss people off, so apologies in advance).

Martin – a very fair offer, for a cabinet you knew I really wanted.

Gavin – for helping me out with the foot pedal restoration.

Frazer – for the gear stick metal work and everything else we have discussed about these cabinets.

Nad – for his limitless knowledge on Atari cabinets and power supplies.

Dan – for all the suggestions on how to make these cabinets run safer and smoother.

Tony – for the online and real world chats, restoration tips and help with the blog.

But for this project, the biggest thanks goes to Jon (aka Lester), who not only fixed these troublesome PCBs, but took the time to talk me through it all, and went out of his way to help me with the cab, at both his home and my own. I’ve learned loads about schematics, the boards themselves, ways to diagnose and understand faults, better ways to solder/de-solder. But above all that, I was bought the best pies I have ever had.

Guys, thank you all.

***

Right then, enough of that silly talk, we have a cab to plug in and see if it explodes…..

This episode follows on from the healthy position we had established in the previous updates, where we had a PCB that was working consistently when benched and a fully restored cabinet, ready to pair with the PCB.

It was time.

In order to assist even further, Jon travelled through to my house, with the working PCB set, as there was nothing more he could do on the bench set up at his home, having only made an adaptor to provide power/ground to the PCB, with no way to test controls, etc. Again, a huge thank you to Jon for taking the time out of his day off, to travel, a not inconsiderable distance, to mine, to help me get this done.

It’s fair to say that it didn’t go according to plan, that further work was required, that a fair amount of heads were scratched, that pies were consumed, that lessons were learned, that schematics were read and faces were redder.

Here’s how the day went……

***

On arrival, we wasted no time at all in getting straight to the important business of the day. Pies. After which, we moved to the games room and pulled Pole Position out from the row and spun it around, ready for poking and prodding.

I have a total of 3 PCBs; two Atari and one Namco. We had taken customs and other chips as required from the two non-workers to help get the best of the two Atari boards running consistently. Jon had soak tested this on his bench and also powered it up a number of times over a number of weeks, to ensure stability.

But this game cabinet is somewhat renowned for boards failing, power surges, edge connector issues, etc etc, and we will, in the next and final instalment be looking into this in more detail and the measures I’m taking to reduce this risk as much as possible.

And even though I had done my part by bench testing and soak testing all the other electronics, there was still an air of uncertainty as we now offered up the PCB towards the open rear of the cabinet.

We decided instead to first connect up the non-working Atari PCB. Of course this wouldn’t work, some of the chips were missing for one thing, but it allowed us to check the voltages under load for the first time, and crucially make any adjustments, on the fly, as needed, without risking damage to the working PCB.

The voltages on the 5v rails were low on both boards. Each of the AR2 boards power each of the PCBs in the dual stack. The AR2 boards have a potentiometer placed roughly in the centre of the board, it’s the only one on the board, which can be adjusted to increase/decrease the power output.

With the power on and Jon metering the voltages, I adjusted the pot until both boards were getting a healthy 5.1v. Again, we let this sit with the power on, for a short while, until we were happy with the consistent voltages given out to the PCB.

Then, we disconnected the trial board and wired in the working PCB. With it connected up and all connections checked and checked again, there was nothing else left, other than to flick the switch.

The inside of the cabinet lit up from the warm glow given off by the coin mech bulbs. Around the front, the fluorescent marquee light flickered into life. Audibly the monitor degaussed itself and powered on, and after what seemed like an age (mere actual seconds) for the screen to warm up and produce an image, we had ……

RAM 2 ERROR.

Really, what the actual feck! I switched it off, said a short inaudible prayer to the Arcade Gods and tried again.

RAM 2 ERROR.

Okay, let’s think this through. As I’ve said, this PCB repeatedly tested fine on Jon’s bench. So why not now. Well, these boards are old, and as fragile as they are flaky. It could easily have just decided to break during the 90 minute car journey, but also to consider at this stage, was this..

On a bench, everything used is new, or relatively so. The PSU is a modern unit, providing a very stable voltage. The edge connector was new, bought specifically to bench this board. The wires used between each section were new, only as long as needed, and had no inter-connectors, so it really is the best possible set up.

Compare that then, to a complex wiring loom, with literally metres and metres of 40 year old, hair thin wire, a power supply unit, with a number of different voltages produced, and two large capacitors to help regulate these, then two audio regulator boards to further reduce and stabilise the voltages, before going through brittle edge connectors, and finally to the PCBs themselves.

That’s a very different set-up indeed. There’s nothing to say it won’t/can’t work, but there are a lot of areas to look into, that might stop it from working.

But before we started to take a deep dive through all of these component parts, we pressed and pushed everything firmly into place, especially the two edge connectors and the voltage connectors on the AR2s and – the error cleared!!

The boot process ran through it’s checks, the start up explosion blasted out through the speakers and the attract screen filled the monitor in glorious Pole Position colours.

With an eagerness that was only bested by the size of the grin that was spreading across my face, I quickly credited up and prepared to qualify…

Except I couldn’t, nor did the game beckon me to do so. Two vital things were missing upon starting a game.

Firstly the iconic “Prepare to Qualify” speech was notably absent. Secondly, I had no steering. But through limping around the track as best I could, everything else that we could test, seemed to test ok.

The short lived hope, would have to wait, as we once again headed back to the pits and the schematics.

***

The work already carried out on the boards and the previous hours poured over the schematic diagrams, had brought a certain sense of familiarity to ourselves, so it was with a certain degree of accuracy that we quickly located the relevant pages. The actual fault however, would allude us for a little longer…..

We started at the very beginning of the steering input phase, the steering wheel.

In the above diagram you can see the specific wiring for the small steering coupler PCB that reads the opto wheel on the steering axle. It has 4 pins, with both the ground showing continuity under testing and the +5v having the required power feeding into it.

So we can tick that off the list. Next is to follow the breadcrumbs and see where this goes.

Using a combination of both physically following the wiring, but also through the schematic, shown below, you can see that this 4pin connector feeds directly into the CPU PCB via the edge connector.

Looking at the very left hand side where the large edge connector is shown and towards the bottom of this you can see the 4 pins, from PS2, feeding into this on pins H, Y, Z and 8. The edge connectors uses pins on both sides of the PCB with the top side labelled numerically and the bottom side, alphabetically.

We already know that the +5v and ground are fine, so that leaves us with Steering 1 on pin 8 and Steering 2 on pin H. First job was to test continuity from the coupler PCB to these pins on the PCB, which both tested fine.

Next up, was to find where these pins then went to on the PCB itself, something that just takes a bit of time and a keen eye to spot it on the relevant schematic page.

Which brings us to the diagram above.

In the middle you can see that of the pins included are our 8, ST1 and H, ST2, which are replicated at the top right of the diagram, going through a number of resistors and into the, (sharp intake of breath), custom chip located at 9K, through pins 26 (ST1) and 22 (ST2).

Now we had these locations, we could check continuity from the edge pin to here, and again this was all okay. With the power back on, and having the advantage of two pairs of hands, the next step was to use the logic probe on these pins whilst the steering wheel was being turned. This provided the needed ‘chatter’ on the probe, indicating that once again, everything we expected to be happening was happening. The signal generated from the opto board and coupler PCB was getting to the custom (said in hushed tones) chip and providing it with the relevant inputs.

So was it a fault within the (shhhh) custom, or was it further along the path. From the schematic you can see that the outputs of the chip are labelled ID0 through to ID7, plus a couple of others labelled 2H and IOSEL, which I think stands for I/O SELECT. Looking across to the left you can see that the outputs ID0 to ID7 are also generated from another (shhhh) custom at 9H. But where do these go?

You can see above that these ID outputs are then fed into yet another (shhhh) custom chip at 9FA, along with the 2H and IOSEL signals, which also feed into, you guessed it (shhh) custom chip 9E.

What is possibly relevant here is that these latter chips, as seen in the diagram above, are part of the sound and speech processor and generator circuits. Remembering that not only did I have no steering, but also no speech at the start of a game.

Being at my house, instead of Jon’s, the testing equipment we had to hand had already been exhausted. We had no way to test these chips, but we did have the two spare boards that we used in the earlier PCB fix entries in this restoration, so the best option we had at this point was to very gently prise these out and swap over the same custom from another board.

You may recall however that the condition of some of these chips was not good, with Jon having already performed some very delicate life saving operations, armed with dremel and soldering iron, which we didn’t want to have to replicate here. But these old chips can be so, so, so fragile, with legs literally falling off, or remaining stuck in the socket, it is little more than an utter lottery.

We crossed our fingers and started with the first custom in the circuit, at 9K. Thankfully this came out really easily and was in really good condition. Swapping it for another made no difference, swapping it for another another, also failed to change anything. It could be that all 3 customs had failed in the same way, but realistically the more likely option is that it was not this chip and the original custom was probably okay, so we replaced the original.

We then moved to the customs at 9F and 9E and this really is where things fell to bits. Not, thankfully the chips we removed, which like the one at 9K were in very good condition, but the ones from the donor boards were shot. Legs broke off, some stayed in the socket, others had been soldered back on previously, they were rusted and corroded and there was no point in even trying to use these.

It was time for a coffee and a rethink.

***

On the previous fix logs, I detailed how we were chasing errors across the board early on, which we later attributed to the poor quality/reliability of the original sockets used across the whole PCBs, which in turn, concluded with the only certain option, leading to Jon methodically de-soldering all the old sockets, and by gosh, there was an awful, awful lot of these, and then re-soldering shiny new sockets into place, completely eliminating any possible issues caused by poor connectivity, and the endless chasing of ghost errors across the boards.

Not only did this work then, but it also helped us here, by ruling out any faults associated with the sockets… Of course this probably was not what was going through Jon’s mind as he trudged his way laboriously through socket after socket after socket after socket, but it was the only way. It was the right way.

But it also meant we found ourselves at an impasse. We didn’t have the tools at hand to test the customs we had in the board. We didn’t have any ‘suitable’ replacement customs on the spare boards to try and swap out the customs at 9E and 9F. But it was close, so close..

And maybe that was the thing that led to the inspired light bulb moment from Jon. We really were so close. The game booted fine, with all ROM and RAM tests passed. The game itself credited up and played. Aside from the speech, it was just the steering, and we knew mechanical and continuity was not a problem. If the custom was bad, surely it would interrupt all the other signals going in/out.

So, Jon wondered if maybe, just maybe, during all the work replacing the sockets, had he nicked a trace, or made a short between two traces with some errant solder, maybe. So we moved into some better light, seperated the two boards, got the reading glasses out and scoured the board.

Flipping the CPU board over, scanning across to column 9 and down to row K, and there it was.

***

Author’s note – my first thought after we got through this, was not to mention any of this, a secret to stay between Jon and I, what happens in the back of a PP cabinet, stays in the back of a PP cabinet.. But to be fair to Jon, as silly as what follows turned out to be, there is a valuable lesson held within, so it is not only with Jon’s blessing that we are going here, but it is with his insistence, and I understand why.

***

Looking at the reverse of 9K, where the socket pins were all neatly soldered into place, the final ground pin, was standing proud, un-soldered and unconnected to the board, floating around in it’s pre-cut hole. Insert Facepalm Emoji here…

A flurry of emotions took over: No way. Yes we’ve found it. Could this actually be the fault. Is this now going to work.

Without a second to spare, the soldering station was on and the pin secured into place. Continuity checked and the PCB reconnected up to the machine.

With knowing smirks on our faces, that could only be shared between two buddies, who had just spent the last 4 hours, sitting on the floor, scouring schematics, printed in a font far too small for my aging eyesight, in a dimly lit games room, wearing head torches that kept blinding the other, I flicked the power switch.

The cabinet came to life, the monitor, the marquee lighting, the booting test screen, the explosion sound, (not the most famous sound of the game, but certainly the one that brings the most joy to all PP owners, as it means you have got), into the attract mode title screen. So far so good.

We both glanced between the screen and each other, and a credit was added. The palpable silence in the room was broken by the iconic speech sample “Prepare to Qualify”. The skin on the back of my neck prickled a little. Could this be it…

The lights turned from red to green and I floored the pedal. As the car sped down the track there was only one thing left to check. I eased the wheel clockwise……… and the car followed. Anti-clockwise, the car confirming my input and moving over to the left. I weaved the wheel from side to side, the car slewing across the track from one rumble strip to the other. Then the first corner was on us and we glided easily around the right-hander, car and driver seamlessly acting as one. Human paired with machine.

My smile grew to a laugh, I spun the wheel, crashing my computer car into the advertising billboard, it mattered not, there would be plenty of time to race later. I can’t actually recall what we did immediately after this. Did we chest bump, fist bump, high five, shake hands, maybe all of the above? Or maybe we were just happy with our lot and relieved. I knew I certainly was.

So there it was, and there you go. What had hoped to be a straightforward test and play, had consumed the whole afternoon, and all because of all the dozens and dozens of sockets, replaced and soldered, of all the chips, replaced and soldered, of all the countless pins and socket legs across the two board sets, one simple ground pin had not been soldered, literally a 5 second fix.

A lesson to us, a lesson to all. Sometimes, even the absolute best of us, which Jon really is, can make a wee mistake every now and then.

But aside from this, it did show that we had understood the schematics, followed the correct path through the diagrams and had ended up at the right chip, where the problem lay, albeit hidden from view by the dual layer PCBs being back to back with each other.

Let us not dwell on this though, it made us laugh, and also reinforced the sterling work already carried out by Jon on his bench, to get this PCB working.

***

So what now. Well, firstly, I’m having a lot of fun playing PP, I utterly love the look of this cabinet, and to have it in the games room, with the attract mode playing, is a fabulous addition. But this game has a reputation and it’s not a great one. Try Googling how many times Pole Position and the word reliable have been used in the same sentence, to get an idea.

And so, the next update on the blog is going to look into, exactly what parts are unreliable, what makes these so, and what we can do to reduce these issues and bring about some reliability. I’m looking forward to this, both the research itself and putting it into practice and into the machine itself.

What I will add to this post is that certain errors are already finding their way into the game, every now and then, random crashes, small graphic glitches, RAM errors, both midway through games or upon booting up. All of these can (I think) be physically linked to the edge connector on the CPU PCB, in as much as simply pressing on this connector will either restore the game, or change the RAM error, etc. But there is a lot more to look at and explore than just this connector, so hopefully you will pop back next time to see how I get on.

For now though it is only right that we finish this weeks post with some wonderful photographs and a wee video of a qualifying lap, where I finished placed….., well you know where I finished…

POLE POSITION

After almost 12 months and a great team effort to get the car onto the start line, I am, at last, prepared to qualify. So if you want to see how that qualifying lap went you can watch it HERE.

Well, there you go, not bad for someone playing one handed whilst filming it in the other hand.

Make sure you come back for the next and final instalment, where we will examine ways to increase this games reliability, maybe even allowing us to move the fire extinguisher to a slightly remoter location..

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Thank you for taking the time to read through, see you all soon for the next instalment.