I have a little bit...and it was around $110 which is not bad for a new CPU board; it really was a fun project. There were two minor issues with the board, first the LED spacing was too close together to for the standard sized LED's but it's workable; I just put the center one (D20) in last and it rests atop the other two, it's barely noticeable unless you are looking for it. The second problem is the spacing of the thru holes is not right for the resistor that sits next to J201, it will fit, but a resistor with a smaller footprint might look better. Like I said, both of these issues are minor and do not effect it in anyway. Did some bench testing after assembly, but this was un-necessary as the board booted right up and works great.

IMG_1704_(resized).JPG
IMG_1705_(resized).JPG
IMG_1706_(resized).JPG
IMG_1716_(resized).JPG

I actually didn't start with a partially assembled board, but purchased the one that was completely blank for $55. ebay.com link: like

I believe this spreadsheet contains the complete parts list (minus the ASIC, CPU, and ROM) I couldn't just use the original Mouser shopping list for this project as it had items for several other projects and I also didn't purchase components that I knew I had; I basically went back and added the missing things I didn't buy, and removed the stuff that wasn't for this project because of this, there may be some errors.

If anyone uses this parts list and/or verifies all the components and finds any errors, please PM me so I know, and can update the spreadsheet. I will post any changes at the end of this post.

https://docs.google.com/spreadsheets/d/1C4znEqZd4K4eywhi__qDwI-3AsX6Y5qdw9Pzb0p178A/edit?usp=sharing

Always happy to help out, I was actually planning on doing a post for this but got distracted with other things; so thanks for making the post. Obviously you will want to start with the smaller parts like the diodes, resistors, and capacitors; then move on to the taller components, this will make assembly easier.

IMG_1666_(resized).JPG

You will also want to have the right soldering tip for the job, I used a 1/64" angled tip for the entire assembly.

IMG_1658_(resized).JPG

I've been considering building one as well. The $110 in parts must not include the ASIC right? I thought I saw someone was selling the entire batch of components as well but I can't find it. I guess it's not that difficult to add the parts to a cart.

So in the auction it shows a bunch of resistors and caps installed... I take it that these are in that list and would not need to be ordered, i.e. that is a list to populate a completely bare PCB?

Yes, this is the list if starting with a blank PCB.

ebay.com link: like

Correct, you will need your own MC6809 CPU, ASIC, and ROM chips.

ASIC:
http://www.planetarypinball.com/mm5/merchant.mvc?Store_Code=PP&Screen=PROD&Product_Code=PPS-5410-12426-01 $60

or for $40

ebay.com link: Williams WPC MPU CPU ASIC Microprocessor 5410 12426 01

CPU:
http://www.marcospecialties.com/control/keywordsearch?SEARCH_STRING=mc6809 $8.95

Isn't replacement MPU's only a little more expensive? Is it time spent soldering these in(*) worth the little aount saved?

(*) - I'm surprised, Pin_Guy, that you didn't use sockets on ALL chips.

Rottendog MPUs go for about $180 *without* the ASIC chip.

Okay, so about $100 in labor. That's not too bad, doing it yourself, then.

Edit: Less, I forgot the cost of the other parts - but still, not that expensive.

Most of the difficult and tedious stuff already seems to have been done. Throw in some resistors and other components, IC sockets, headers, and you're basically done.

The LEDs used on these boards ARE actually a standard sized part.

"Standard" LEDs are 5mm whilst these use the smaller 3mm LEDs.

They are a very standard part and easily available.

For those that like the repair and electronics side of pinball this is an excellent project and well worth the time and effort IMO. It's not about saving money but it's a great learning exercise and the satisfaction of seeing something come to life that you built from a bunch of parts just can't be beat!

It's true, the price difference between a pre-assembled board and building it is not so great, but then I would miss out on all the fun building it myself. I just worked on it during my spare time ... an hour here an hour there until it was finished.

I thought about installing sockets for all the chips and decided against it for a couple reasons. I have to right equipment to pull chips from the board intact, and also by direct solder them, I'm able to inspect all the solder joints. I found this to be more beneficial than having the ability to snap in replacements.

Edit: this post was edited for clarity and grammer

As a general practice, whenever I install chips, they always get socketed. Saves time later when/if a problem pops up. Plus, you don't have to heat the board multiple times and adding and removing components.

most folks do prefer that, the beauty of building a spare board is I get to swap it in and work on the bad one at my leisure; plus I enjoy soldering and working on the boards and am under no time constraints

I would not use sockets for anything but ASIC, ROM, RAM and 2803 at time of initial assembly. Sockets = potential for future connection problems. Perhaps at time of future replacements if parts fail, then they should be socketed.

I've actually moved away from sockets in some of my repairs. WMS 3-7 boards, I no longer socket anything under 22 pins unless the board has had previous rework and has questionable traces. The original traces are robust enough that they can be desoldered and resoldered many times. Sys9 and later, I use sockets on nearly every IC, with few exceptions.

If I were building one of these, I'd prefer to buy one of the ones Mr. Pinball Australia sells, because it's an original board. Matches the schematic, etc. And looks original when done.

I actually have prototype WMS CPU blanks (red) for WPC-S and WPC-95 CPUs. I've kicked around building them out, but I think I'm going to leave them as-is to admire them. Maybe a shadow box sort of wall hanging display to put in my gameroom. Also have WPC-89 DMD controller and Fliptronics 2 board to match - never could get a sound or driver board to match). I have a NOS proto WPC-89 CPU that was built but didn't work to go with them. I fixed it (prototype, had a bad trace on the back side, and missing the crystal).

I considered one of these as a fun project, but until I'm caught up with customers work 100%, my own stuff continues to gather dust. I'm getting close!

I dated myself when I said standard size

always please socket the ULN2803 switch matrix chip (at minimum) when making one of these. Heck Williams even socketed that chip (starting with WPC-S and going to WPC-95). There's a reason they socketed that chip...

I didn't mean to start a debate about the sockets, honest. IMHO, i'd socket everything - the risk of a bad connection in the socket (when using good, quality sockets) is much preferred for me over having to replace a chip. Again, that's my preference if I was making one.

Ya'll can do what you want, of course.

Is the component refs and values the same as a standard WPC board? (i.e. C1 on this board is the same as C1 on the OWM board?)

No worries, everyone is entitled their own opinions. If I was to make this board for someone, I would make it how they wanted it.

To answer your question, all of the reference designations are part-for-part compatible with the Williams board; The component layout is also very similar, not exact, but pretty darn close.

There was a link to the BOM in the ebay listing

http://www.bobsokol.com/ebay/WPC/WPC2A_1.txt

TWOBITS.COM
4418 PACK SADDLE PASS
AUSTIN TX 78745
512-447-8888
[email protected]
HTTP://WWW.TWOBITS.COM
-------------------------------------------------------------------------------
WPC MPU BOARD BILL OF MATERIALS
-------------------------------------------------------------------------------
WPC2A_1.PCB Bill of Material Summary
-------------------------------------------------------------------------------
DESCRIPTION QUAN. COMPONENT DESIGNATOR(S)
-------------------------------------------------------------------------------
----- ALL RESISTORS 1/4W UNLESS OTHERWISE SPECIFIED

ZERO OHM JUMPER 9 W1,W4,W7,W13,W14,W15,W16,W17
W18

470 OHM 9 R5,R6,R7,R8,R12,R13,R87,R88
R89

1K 25 R43,R44,R45,R46,R47,R48,R49,R50
R51,R53,R55,R57,R59,R61,R63,R65
R67,R68,R69,R70,R71,R72,R73,R74
R84

1.2K 16 R52,R54,R56,R58,R60,R62,R64,R66
R75,R77,R78,R79,R80,R82

1.5K 6 R1,R2,R3,R4,R93,R97

1.5K 1/8 WATT 1 R96

10K 29 R14,R15,R16,R17,R18,R19,R20,R21,R22
R27,R28,R29,R30,R31,R32,R33,R34,R35
R36,R3,R38,R39,R40,R41,R42,R86,R90
R94,R98

470K 1 R92

1M 2 R95,R99

2.2M 1 R91

4.7K x 9 BUS RES NET 1 SIP1

----- ALL CAPACITORS AXIAL LEADS, X7R OR Z5U UNLESS OTHERWISE SPECIFIED

22pF AX CONF 4 C2,C29,C30,C34

100pF AX CONF 1 C28

470pF AX CONF 24 C3,C4,C5,C6,C7,C8,C9,C10,C11,C12,C13
C14,C15,C16,C17,C18,C19,C20,C21,C22
C23,C24,C25,C26

1000pF AX CONF 2 C32,C33

.022uF AX CONF 1 C50

.047uF AX CONF 1 C27

.1uF AX CONF BYP CAP 16 B1,B2,B3,B4,B,B6,B7,B8,B9,B10,B11,B12
B13,B14,B15,B16

100uF 16V AX AL ELEC 1 C31

FILTER CHOKE 4.7uH 1 L1

32.768KHz FORK XTAL 1 X1

8MHz CRYSTAL 1 X2

1N4148 DIODE 17 D2,D3,D4,D5,D6,D7,D8,D9,D10,D11,D12
D13,D14,D15,D16,D17,D18

1N5817 DIODE 2 D1,D25

RED LED, T1 (3mm) 3 D19,D20,D21

2N3904 NPN BIP TRANS 1 Q1

SN74LS244N 3-ST DVR 3 U1,U2,U7

SN74LS245N OCT BUS XCV 1 U3

68B09EP PROCESSOR 1 U4

SN74LS14N HEX SCH TRG 1 U5

GAME ROM, 27C040 1 U6

M48Z58Y-70PC1 ZPRAM 1 U8

WPC CUST 5410-12426-01 1 U9

MC34064 SUPERVISOR 1 U10

SN74LS240N OCT INV DVR 4 U11,U12,U13,U15

SN74LS374N OCT LATCH 1 U14

LM339N QUAD COMPAR 4 U16,U17,U18,U19

ULN2803 8-CH DARL DVR 1 U20

MC14584BCP HEX SCH TGR 1 U21

40-PIN LP SOCKET 1 U4A

32-PIN LP SOCKET 1 U6A

28-PIN LP SOCKET 1 U8A

84-PIN PLCC SOCKET 1 U9A

14-PIN LP SOCKET 4 U16A,U17A,U18A,U19A

18-PIN LP SOCKET 1 U20A

26-PIN .100 DUAL HEA 2 J201,J204

34-PIN .100 DUAL HEA 2 J202,J211

-----ALL HEADERS FRICTION LOCK TYPE

12-PIN SER KK .100 HDR 1 J205

9-PIN SER KK .100 HDR 4 J206,J207,J208,J209

7-PIN SERIES KK .156 1 J210

8-PIN SER KK .100 HDR 1 J212

TRIPLE AA BATT HOLDR 1 BP1

MOUNTING HDW FOR X2 1 ---- USE MOUSER PART NO. 749-CI-192-050-3

===================================================================================
PARTS NOT USED
--------------
NO PART ON ORIG PCB 1 C1

3-PIN SER KK .100 HDR 1 J203

ZERO OHM JUMPERS 9 W2,W3,W5,W6,W8,W9,W10,W11,W12

http://provider1.cart.net.au/epages/mrpinballtrial.sf/en_AU/?ObjectPath=/Shops/mrpinballtrial/Categories/%22Circuit%20Boards%22

Don't see anything on his site.

I checked earlier. There were complete MPUs listed, but they were out of stock.

http://provider1.cart.net.au/epages/mrpinballtrial.mobile/en_AU/?ObjectPath=/Shops/mrpinballtrial/Products/WPC089-TH

No debate, just good to do

and the two LM339 chips next to it

Looks like he may have sold out.

He still has WPC-S

ebay.com link: Original WPC S CPU Board Bare Genuine NOS Part Mr Pinball Distribution

i think socketing the LM339s is less of an issue. i mean sure why not, but generally the LM339's only seem to go "bad" when battery corrosion is involved (and sockets won't fix that). at least in my experience. but that ULN2803 man it's easy to smoke those. that's a *must* socket part in my mind.

i know people that have gone through 10+ of those ULN chips when trying to figure out a switch matrix issue. A friend of mind had a Twilight zone that was shorting 50 volts through a wire form and down other metal parts so that only when the ball rolled to a certain part of the playfield, the circuit will be complete, and the ULN would die. I think he said he smoked 15 of those chips trying to find that problem!

Had that EXACT same problem a few months ago. I not only blew 12 of the 2803's, but 2 of the chip farther up the line. (I socketed that the first time..) (OT, but my issue was the Gumball Diverter - lug had shorted on the bracket, which was connected via diverter to the ball lock cage, which was the connect to the right power ramp. My mini powerfield entrance switch had a loose wire and was shorting to it's holder. So when things were *just right* and the ball came off the wireform to the entrance to the mini pf, if it made contac with the metal guide, it'd short out and blow the 2803..)

Was a pain in the arse. It's why I pretty much like just socketing everything - You never know what could happen.

Another example! In one of my genius moves 7 years ago, I had both the Fliptronics and Audio board out of my TZ. Reassembled them both, and reversed the Fliptronics +50v coil volt plug with the audio board's +12/+5v plug. I sent +50v through the bus lines - it fried the audio board, display driver board, and numerous chips on the MPU board. (The two plugs are keyed *exactly* the same, and are directly opposite each other.)

So, THOSE are not socketed in my game as well. So, no matter what happens.. something will always cause you to wish you didn't have to unsolder a chip. ..Either that, or I just suck.

I went ahead and added ALL the IC sockets to the spreadsheet under a separate "Optional Items" category including P/N and prices from Mouser; this way people can pick and choose what they want to socket. I've also added reference designators for every part.

https://docs.google.com/spreadsheets/d/1C4znEqZd4K4eywhi__qDwI-3AsX6Y5qdw9Pzb0p178A/edit?usp=sharing

I have all 3
Wpc
Wpc-s
Wpc-95

All nos blank boards

An updated BOM for the missing parts:

http://www.bobsokol.com/ebay/WPC/incBOM.htm

Description
QTY
Component Designation
----- ALL RESISTORS 1/4W UNLESS OTHERWISE SPECIFIED
4.7K x 9 BUS RES NET
1
SIP1

----ALL CAPACITORS AXIAL LEADS, X7R OR Z5U UNLESS OTHERWISE SPECIFIED
100uF 16V AX AL ELEC
1
C31
FILTER CHOKE 4.7uH
1
L1
32.768KHz FORK XTAL
1
X1
8MHz CRYSTAL
1
X2
RED LED, T1 (3mm)
3
D19, D20, D21
2N3904 NPN BIP TRANS
1
Q1
SN74LS244N 3-ST DVR
3
U1, U2, U7
SN74LS245N OCT BUS XCV
1
U3
68B09EP PROCESSOR
1
U4
SN74LS14N HEX SCH TRG
1
U5
GAME ROM, 27C040
1
U6
M48Z58Y-70PC1 ZPRAM
1
U8
WPC CUST 5410-12426-01
1
U9
MC34064 SUPERVISOR
1
U10
SN74LS240N OCT INV DVR
4
U11, U12, U13, U15
SN74LS374N OCT LATCH
1
U14
LM339N QUAD COMPAR
4
U16, U17, U18, U19
ULN2803 8-CH DARL DVR
1
U20
MC14584BCP HEX SCH TGR
1
U21
26-PIN .100 DUAL HEA
2
J201,J204
34-PIN .100 DUAL HEA
2
J202,J211

-----ALL HEADERS FRICTION LOCK TYPE---------

12-PIN SER KK .100 HDR
1
J205
9-PIN SER KK .100 HDR
4
J206, J207, J208, J209
7-PIN SERIES KK .156
1
J210
8-PIN SER KK .100 HDR
1
J212
TRIPLE AA BATT HOLDR
1
BP1
MOUNTING HDW FOR X2
1
---- USE MOUSER PART NO. 749-CI-192-050-3

===================================================================================
PARTS NOT USED

--------------

NO PART ON ORIG PCB 1

C1
3-PIN SER KK .100 HDR 1

J203
ZERO OHM JUMPERS 9

W2, W3, W5, W6, W8, W9, W10, W11, W12

I really don't care for this BOM since its basically a copy of the MPU89 parts list from 1994. This BOM is useful for telling you what parts you will need ,but its more of a rough guide of what you need to buy. If you use this list as well as the Google Sheets document I linked it will make your life easier as there is an actual link to Mouser Electronics for every single part on this board.

Forceflow, if you want to use a copy my Google sheets and trim it down to what is needed for the partial assembly, you have my permission to do so.

That would be perrrrrfect

I don't see it listed on the original WPC parts list. Not all components are always populated.

[edit]: It is one of the jumpers to set the RAM size:
http://pinwiki.com/wiki/index.php?title=Williams_WPC#Jumpers.2C_RAM_and_ROM_size

pasted_image (resized).png

R93 isn't necessary if using a 62256 for RAM.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

as others mentioned, R93 is not populated with this configuration. The board booted perfectly and I use it for testing, its the test board I used in this post https://pinside.com/pinball/forum/topic/the-mysterious-switch-matrix

Ed, would it be possible to order from you and say "I need a set of components for the partially assembled WPC89 boards" and then you ship exactly what is needed?

If so, I'm in as I think this is a fun project to tackle.

Unless I'm mistaken, there are two components (aside from the CPU, ASIC, and EPROM) that aren't on the GPE site:

FILTER CHOKE 4.7uH 1 L1
CI-192-050-3 (Circuit Board Hardware - PCB Crystal Insultr Tabs 2-Lead Nylon White) for X2

I think everything else is available.

if you can't come up with a part lists on and order it from GPE's website you probably are not going be able to populate the board. Effort level too low!

I didn't use this as the only thing the outer case can short to is ground, and if it does its going to act as a shield for the crystal so there really is no downside to not using it.

Thanks for posting, I'm going to manufacture another from a bare board as I already have enough components lying around to do it ... without the ASIC, ROM, and CPU chips. I recently noticed the first on I made had one of the ceramics turned the wrong way making the writing on it upside down ***gasp***

This is very problematic as shipping of these few items is going to be 3-4 times the cost of the parts

The choke can be bypassed. I jumper it on a lot of CPUs I do alkaline repair on. The choke is available from Australia but is very expensive.

Let me dumb it down for you. It would be handy for people that are not currently customers of Ed's to be able to select a 'kit' and order it. It would also be good business sense for Ed for those wanting to order it since more and more people are starting to do these projects.