Wow. It seems the word "unprecedented" is being used a lot but the Pacific Northwest really did just experience an unprecedented heat wave. I was in the region for the previous all time high of 103F in July 2009. I remember that day. The region just experienced three straight 100F+ days.

I have an external thermometer (not super accurate but reasonable), an internal thermostat and an upstairs thermometer.

• Saturday was 103F outside.
• Sunday was 107F outside.
• Monday (the peak) was 112F outside. Inside peaked at 96F main level and 99.99F upstairs.

Needless to say no soldering in that kind of heat! In fact ... no work at all in that kind of heat. Sit in front of the fan and binge watch TV. A welcome break from work but comfort was lacking.

https://pinside.com/pinball/forum/topic/project-pinball-auction-2021#post-6357584

It's been quite a few weeks and I had to get them built after completing some other builds from weeks before the board fabrication order. Thanks to Brad jellikit for his work at Project Pinball. I am very happy to be able to contribute! If anyone has items (or perhaps services) to contribute I am sure that Brad would love to hear from you.

I have been working on this for most of the past three weeks straight to the exclusion of pretty much EVERYTHING else. These boards (especially the big boards) take time. I also acquired three (local) boards in that time that are awaiting repair. Two have been waiting for almost two weeks now. Fortunately I provided a loaner to keep the machine running. I thought I was going to have a nice relaxing summer.

Sneak peek. It's a software rendering and the limited screen real estate of my laptop prevents a more detailed image. There's nothing like a physical board. It went into fabrication mid last week and it is now awaiting shipping. I have returned to building boards that were put on hold so I could complete this board. I need to build those boards as the recipients have been waiting patiently. I will likely find the time to squeeze building this board and although it is likely I will be able to bench test it I do not have a physical machine to do actual testing. I need to find someone local who has a machine and is willing to let me try it. More details will be supplied when I have the physical board unless there is demand for the information now.

sneakpeek.jpg

This works. I haven't tried it on my board but I do know that everything I have read about the procedure and the way the board address decode works indicates that it will work. It does require ROM preparation. The big disadvantage is that the mounting holes are upside down. Another disadvantage is that you will likely have to do your own troubleshooting if something goes wrong. I have seen a thread or two asking for help on this forum (specifically related to System 9 software on System 11 hardware) but it seems most people either don't know much about this procedure or don't see the threads in order to be able to provide assistance.

It's a software rendering. The rest of the machine is not RoHS compliant so I don't make the boards that way. It would seem pointless to me but I could be wrong.

I am guessing the heat sink does not get too hot. It's a 6021/6030 so it does not dissipate too much heat (unlike the 5298). I have not measured the operating temperature so I could be wrong.

Yes. I don't bother with "naked" headers. If I'm going to the trouble of making a new layout then I am going to move things around to make sure that shrouded headers will fit. I did this with the WPC-89 CPU board. The original board (or newly available re-prints) do not have enough space to fit the shrouded headers unless you cut one edge of a connector. I have to do this when I retrofit the shrouded headers to an OEM board.

sneakpeek_1j20.jpg

I looked for a manufacturer and merchant that sells ejector style headers but I haven't purchased any. It takes a lot of board real estate (relative to the shrouded header). With these System 11 boards I changed the hole from a regular round mounting hole to a keyhole style hole and that takes not only more real estate but also real estate that you cannot route a trace through (because it's a hole and therefore there is no board). It is possible to pack components tighter but the tighter you pack components the harder it is to service in the future or even install when building. I try to space components and traces evenly as well as adhere to a general clearance for manufacturing. This System 9 CPU board was a gift in terms of unused board space. I took advantage of it to add things and retrofit circuit improvements made in System 11 while trying to stay true to System 9 and the original circuit designs.

It's just a color setting. It's the software default. I actually don't see the colors. I just see the layout, traces and silkscreen.

The software render is built-in to the CAD software. It is not a gerber viewer so I guess it can take advantage of some internal knowledge it has rather than interpreting the gerber files. I generally don't export to gerber until I am ready for manufacturing. It would be an additional step for viewing which doesn't add much but rather takes more time.

Physical boards arrived today. Mixed bag of things but one board with some interest.

Disclaimer: The following text is intent (design). I need to build an actual board and verify it works on my bench before proceeding to a machine to verify it there.

The System 9 CPU board. It is 100% compatible with the original design. Speech is implemented on the external speech board (C-10716). There is an optional daughter board that implements speech but has special requirements.

In the original setup sound software (U49) is contained on a 27128 ($4000 or 0x4000 bytes) located at $C000 in the address map. The speech software (U4-U7) is contained on 4x 2732 ($1000 bytes) for a total of $4000 bytes located at $8000 in the address map. The external speech board also implements CVSD and analog mixing of the CVSD output.

When installed and correctly configured the optional daughter board obviates the need for the external speech board. In this setup the ROM at U49 is switched to a specially prepared image written to a 27256 ($8000 bytes). The image contains the 4x 2732 speech images at offset $0000 to $3FFF and the original sound image at offset $4000 to $7FFF to meet the address map requirements. The daughter board implements the CVSD and analog mixing. This requires special ROM preparation so it is not for everyone.

boards_163.jpg

Detail of the upper center of the board. This area implements the lamp columns and switch matrix. It shows:

• The silkscreen explaining the daughter board and jumper configuration for it.
• The silkscreen for the general jumper configuration.
• The lamp column modifications. The circuit no longer supports the original BJT TIP42 circuit. That circuit generates too much heat. It also takes more board space and it was difficult to squeeze in the circuit to allow BJT or MOSFET installation. I simplified things and made the executive decision to only use MOSFETs. I think it's the right thing but others may disagree.

boards_164.jpg

Detail of the lower left quadrant of the board. This area implements the display signals and the special solenoids. There are minor changes to the display signal circuit and improvements to the special solenoid circuit. Completely NEW layout of the entire area. It shows:

• The 74154 (4:16 decoder) IC is now implemented using 2x 74HCT138 (3:8 decoder) ICs.
• The 470pF capacitors added in System 11 have been back ported.
• The two factory added capacitors on original boards are now placed on the board.
• Each special solenoid drive now has a fuse holder (or clips). This is optional and a wire can be installed if not desired.
• The Zener diodes added in System 11 have been back ported. These are incorrectly located in the optional area. This will be fixed in the next revision but the board is electrically correct.
• New special solenoid diagnostics.
  • A set of switches that are identical to the playfield triggers (not implemented as RC).
  • A set of LED indicators to show trigger state (LED is ON when trigger is closed).
  • A switch to disable or enable these diagnostic features.

boards_165.jpg

Detail of the lower right quadrant of the board. It shows:

• Game RAM is 6116 or 6264. The original board only supports 6116. This allows either 6116 or 6264 NVRAM to be used.
• Sound RAM is 6116 or 6264 not 6810. The 6810 is difficult to find. The best thing is to use a 6802 and not even bother with this RAM.
• On board diagnostic switches in case coin door diagnostic switches fail. Can be disabled or enabled.
• Centralized jumper configuration area. Descriptions of the jumper configurations are located at the center of the board as there is no space available for the text.
• Difficult to see in the image but the MAN72A has been replaced with LSHD-A101. The MAN72A is difficult to find. The LSHD-A101 (or LSHD-7801) is much easier to find. It is conceivable that this can be changed again if parts become difficult to find or a daughter board to translate signals could be made.

boards_166.jpg

Close up of the speech daughter board.

boards_167.jpg

I need to start building this to get an answer to the question as to whether the board works. I have a potential engagements that may slow down building and I need to find/arrange testing in a physical machine. If the board works then bare boards will be available immediately. Complete boards will be added to the end of my work queue. I only had 5x boards made in this initial fabrication request. I know I need to revise the board (the Zener diodes need to be moved out of the optional area) so once these initial 4x boards (the first one is not available as I keep it for reference and assuming the board works) are gone there will be another delay before the next batch of boards become available.

Now ... need to start building.

Scatter brain. <sigh>.

Two minor things in the boards that recently arrived.

Twilight Zone boards. The 8 High Power Driver board and the 2 lamp (door) flasher board. These boards were made by special request but are available to anyone that wants them.

boards_168.jpg

The speaker pop elimination system for WPC-95. It definitely eliminates the pop at power on and the pop after power off but the pop just before the bong is NOT eliminated. There is no easy way to eliminate that.

boards_169.jpg

Better late than never. I spent the weekend building the System 9 CPU board. I wanted an answer if it worked or not and if not what the problems are so I have an idea of things to examine. I like to have low priority threads going on. You never know when the penny will drop on what is causing problems.

Finally ... after a long time in development ... the board works (on the bench). All tests passed. Including the sound and speech. I don't have an external speech board so I haven't tested that aspect but I prepared the special ROM (combined sound and speech) and it works. I also tested 6808 with 6264 as well as 6802 without 6264 for the sound. Display works. Sound/speech works. Solenoids work - controlled and special. Switches work. Special solenoid diagnostics also works.

boards_170.jpg

I added a coin and started a "game". The display shows "00" for the score but the timing of the image doesn't show it.

boards_171.jpg

The complete board (right side up). The 2x20 ribbon header is not populated as I need to order the part.

boards_172.jpg

While building it I found one very minor silkscreen error. The key for the power (1J17) connector. The board is electrically correct. There are a few other things that will be tweaked. I still need to test in a physical machine but I have never had an instance of a board passing on the bench but failing in a machine due to a board issue. Failure in a machine is always an issue with another board or the wiring of the machine.

The four remaining boards I have are available if anyone has been waiting and wants one immediately. If/When those are gone there will be a delay as I need to make the modifications and have the next revision fabricated. The BOM is mostly the same as the OEM board but there are some IC and electrical changes to "modernize" it. The obvious changes are:

1. Replacing the 3x BT97/74365/74367 (3x6 buffer) with 2x 74244 and 1x 74125 (2x8+1x4 buffer).
2. Replacing the 1x 74154 (1x 4:16 decoder) with 2x 74138 (2x 3:8 decoder).
3. Replacing the 6116 with the option for a 6116 or 6264.
4. Replacing the 6810 with a the option for a 6116 or 6264.
5. Removing support for the TIP42 and only supporting MOSFETs in the lamp column drives.
6. Replacing the MAN72A with LSHD-7801.
7. Adding
   • 24x 470pF capacitors.
   • 6x Zener diodes.
   • 6x fuses to individual fuse the special solenoid drives.

Bare boards are available immediately. I will be updating the BOM document in the near future. Complete boards will be added to the end of the work queue.

Now (really) back to building boards requested from over a month ago.

Got back from testing in my friend James' Sorcerer.

boards_173.jpg
boards_174.jpg

Both configurations work. Shown in the images is the unified (stand alone = does not require OEM speech board) configuration.

• Original ROMs (2764+2732 game and 27128 sound) with OEM speech board.
• Unified ROMs (27128 game and 27256 sound+speech) with daughter speech board.

Special solenoid diagnostics work as expected.

This board is officially ready having passed the final test. The list in the initial post will be updated shortly.

Apologies for not replying sooner. I try to minimize posts in order to prevent unnecessary bumps or making the thread state "on fire".

There are couple of responses to your suggestions.

• I agree that WPC transformers can be difficult to find if one has been damaged. It is possible to replace the multiple windings in the transformer with transformers that have separate windings. I do this on my bench. For the power board there are five separate windings. For the sound board there is a center tap winding which requires a transformer with such connections. I don't have a transformer for the high voltage for plasma displays. I'm not a fan of the plasma displays due to the heat dissipation in the voltage regulation circuit. I also try to avoid high voltage on my bench. I don't like getting zapped or having the potential to have some form of cardiac arrhythmia while working on stuff.
• One issue with aftermarket switching power supplies is that they might not be able to provide sustained current at the required voltage. It will depend on the switching power supply product that you use but it is worth noting what their rated current outputs are. It is also worth noting that if you buy from Chinese merchants (or Chinese products) that their specified ratings might not also be true or accurate.
• The problem with providing headers for some external DC power is that there is not a lot of space left on the original board. I already consumed more space than the original by replacing the bridge rectifiers with discrete diodes. It is possible to make more space by pushing components closer together (much like what was done in WPC-95) or by replacing discrete resistors with resistor networks. Of course the ultimate way to make more space is to switch some components to surface mount. The bottom line ... nothing is free. In order to add some feature something else has to give.
• I am currently working on a power board (in the copious amount of free time that I don't have) but I honestly doubt I will be able to add such a feature. For the reasons previously provided. Typically it is space restraints. The board physical dimensions and mounting holes are static ("anchored") and cannot be altered. The only easy way to add things is to use a daughter board but I would prefer not to do that for power requirement. The other issue with daughter boards is that they also create "anchor" points. This creates hazards when laying out tracks on the board.

Everybody has different life experiences and different life perspectives. The more thoughts and ideas ... the better. This is how the best products are made. Feedback given. Feedback either accepted or rejected. When rejected a good reason should be provided.

Transformer windings that are not fused could overheat from excessive current draw. This would cause the wire insulation to fail and potentially short rendering the winding worthless. As previously mentioned it is possible to replace the single transformer containing multiple windings with multiple transformers containing a single winding. If a transformer with the required ratio cannot be found it is possible to chain multiple transformers to achieve the desired ratio. A less than ideal solution. A solution that will work if the part is not available.

Brief update.

I had been board building for weeks but last week I took in some boards for repair. Boards all local. Two alkaline corroded and one "no boot".

1. A WPC-89 CPU board with light alkaline corrosion. The corrosion was reasonably well spread affecting U15, U16, U17, U20 and some of the resistors/capacitors below. A few traces had been corroded away. It was repaired over the course of two days. I spent less time repairing this than it would have taken to build a new one.
2. A System 11A CPU board with light alkaline corrosion. Mostly affecting the legs of ICs (in the "corrosion zone") but affecting the entire reset section and some of the power input capacitors. Repair didn't go smoothly. I spent two and half solid (mostly full) days working on this board. Equivalent to the amount of time to build a new one. Building a new one however is not as frustrating as figuring out why the board does not start correctly after repair.
3. A System 11B CPU board presenting as "no boot". This one was interesting. Leon ROM passed. Game ROM does not work. Some game ROMs did not report any errors (Taxi and Black Knight 2000). Other game ROMs (Swords of Fury and Police Force) reported error code 9 (IRQ failure). After much fighting I got it working. There was one incident where it reverted to the previous error code 9. Then it went away and started working. It has stayed working since. I have definitely spent less time on this than it would have taken to build a new one but ... it was more frustrating (I am still a little puzzled at the potential instability) and worrying about potential re-emergence of the failure. For the moment the board works but I suspect it may re-present at a later time. At that time I would recommend replacement. The board is fragile enough (from age) and I had to do some trace repairs even though I was being as careful as possible when removing ICs.

Conclusion: I will probably stop accepting alkaline corrosion repairs and just switch to building new boards. I like to keep my blood pressure in check and dealing with alkaline corrosion is a sure way to raise it. Not to mention that lovely smell of alkaline permeated solder when you heat it up. That smell is unmistakable.

As a reminder to people who may be reading I do offer complete (built) boards but I am not fast at building so if you're patient and would like a complete board they are available. I may be providing longer lead times in the near future (will not affect boards already accepted for building) as I have recently accepted a machine restoration job that will take time away from building boards.