(Topic ID: 102035)

WMS Type 1 v1 Sound Board upgrade notes

By barakandl

7 years ago


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  • Latest reply 6 years ago by barakandl
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    Type1 V1 a.jpg
    Type1 V1 b.jpg

    #1 7 years ago

    Here is some information that is not well published regarding Williams Type 1, Version 1 sound boards.

    Per a WMS service bulletin, add two 10k resistors to open pads (See my pic) to "reduce susceptibility to noise".

    To use a WMS "SOUND 1" labeled ROM or a 2716 EPROM containing the "SOUND 1" rom you need to do some modifications...

    1. Change R14 and R23 to 4.7K resistors.

    2. Solder pins 39 and 40 together on the 6820/6821 at IC3. If you do not do this, the PIA will not respond to the input connector being grounded yet the diag button will still produce sound. THIS APPLIES TO THE TYPE1 V2 AS WELL.

    3. Change jumpers to as seen in my pic. THIS APPLIES TO TYPE 1 V2 AS WELL.

    To use a 6821 PIA in place of a 6820, you need to do some jumpering on the V1 board (this is done by the factory on most sound boards except on very early ones). See my pic, it easier.... Blue Jumper wires on the solder side.

    The V1 sound board is 100% compatible with V2 games like TimeWarp, Laserball, and probably even the arcade games that used the V2 board. These mods allow the board to be rebuilt more easily. Without knowing some of these tricks you can be left very confused why the board doesnt work right or only with certain components.

    Type1 V1 b.jpg
    Type1 V1 a.jpg

    Hope this helps

    Andrew

    #2 7 years ago

    Wow! Wiki-Worthy. Or at least a great 'sticky' thread.

    Nice hi-res photos too.

    Thanks for the info!
    faz

    #3 7 years ago

    As always, full release on my pics, text, all info, to do whatever you want with them. I want the tech info to be available to anyone for free (harumph GTB...).

    #4 7 years ago

    Andrew....do you have the info for the blue jumpers that are in the picture.
    I've seen that on those boards before.
    --
    Chris Hibler CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.nt/chibler/Pinball/index.htm
    http://www.PinWiki.com - The Place to go for Pinball Repair Info

    #5 7 years ago

    Hi Chris,

    I wish I knew / understood the theory. All i got is if you want to use a 6821, the jumpers have to be in place. One is on the RESET line which is a clue. Another looks like it attaches a pullup(down?) resistor that would be otherwise unconnected. Searching on RGP i found a few posts over the years remarking my same findings, yet no theory behind it.

    #6 7 years ago

    Thanks for posting this. I've been messing with a Type 1 sound board from a Flash that was sold to a friend as complete but may have issues. It will work when the diagnostic button is pressed, but it will not work in the game. None of the usual suspects are bad (PIA, NAND, buffers, CPU). I remember skimming over something about this when searching RGP, but I hadn't had time to investigate it. Now that I look closer at the board I see it has sound ROM 1 but pins 39 and 40 are not soldered together. I'm now wondering if someone stuck a ROM 1 in a sound board and put it in the game to make it complete and get it ready for sale. Hopefully I'll get a chance to check this out soon, I'll report back.

    #7 7 years ago
    Quoted from stangbat:

    Thanks for posting this. I've been messing with a Type 1 sound board from a Flash that was sold to a friend as complete but may have issues. It will work when the diagnostic button is pressed, but it will not work in the game. None of the usual suspects are bad (PIA, NAND, buffers, CPU). I remember skimming over something about this when searching RGP, but I hadn't had time to investigate it. Now that I look closer at the board I see it has sound ROM 1 but pins 39 and 40 are not soldered together. I'm now wondering if someone stuck a ROM 1 in a sound board and put it in the game to make it complete and get it ready for sale. Hopefully I'll get a chance to check this out soon, I'll report back.

    Solder together p39 and p40 of the PIA at ic3 and I bet you are good to go.

    #8 7 years ago

    Good stuff. Did not know about the need to jumper the board for 6821.

    The mod for sound ROM 1 is documented in the Flash manual. Any board without this mod likely predates Flash.

    viperrwk

    #9 7 years ago

    No worky. Must be something else wrong.

    I also realized thanks to your post that I need to be testing with a 6820, not a 6821. I don't have any 6820s on hand. So I'll need to try and rule out the PIA being the problem as my previous attempt isn't valid.

    #10 7 years ago
    Quoted from stangbat:

    No worky. Must be something else wrong.
    I also realized thanks to your post that I need to be testing with a 6820, not a 6821. I don't have any 6820s on hand. So I'll need to try and rule out the PIA being the problem as my previous attempt isn't valid.

    Check out the buffers on the signal input. I have seen a bad buffer on the silence input which can cause your same symptom.

    #11 7 years ago
    Quoted from stangbat:

    I also realized thanks to your post that I need to be testing with a 6820, not a 6821.

    6820/6821s are completely interchangeable. No need to source a 6820.
    --
    Chris Hibler - CARGPB #31
    http://www.Team-EM.com
    http://webpages.charter.net/chibler/Pinball/index.htm
    http://ww.PinWiki.com - The Place to go for Pinball Repair Info

    #12 7 years ago
    Quoted from ChrisHibler:

    6820/6821s are completely interchangeable. No need to source a 6820.

    That's what I've always heard. Perhaps Andrew can comment on his instructions for jumpering the board to use a 6821 in place of a 6820.

    #13 7 years ago

    It is working. Here's a summary and the chain of events:

    -Test sounds when the test button was pressed. No sound during the game or when grounding the respective transistors
    -Board has Sound ROM 1 but PIA pins 39 and 40 were not jumpered
    -Tied pins 39 and 40 together, no change
    -Replaced both buffers, sound works

    Here's the funny thing, previously I changed both buffers and it didn't work. But that was without pins 39 and 40 tied together.

    I then tried different combinations of one old buffer and one new and it behaved like before, i.e. the only sound was with the test button, none any other time. Basically it would not work if either of the old buffers was installed in any combination with a new one.

    So in summary, with pins 39 and 40 tied together and two new buffers, it works.

    #14 7 years ago

    This is the only situation where there is compatibility issues with using a 6821 in place of a 6820. I confirmed it on three sound boards.

    In all other situations I know of (pinball) 6820\6821 are completely interchangeable.

    I was hoping someone knew the theory. I think it is how they program the pia how to operate.

    #15 7 years ago

    The difference between the 6820 and 6821 (from the datasheet) is that the 6821 also has two TTL drive capability on all A and B side buffers, being TTL compatible and support for static operation. There are also some subtle differences on the timing side of things. Perhaps we can get Ed to chime in here.

    viperrwk

    4 months later
    #16 6 years ago

    Another thanks to barakandl for this thread. I just finished working on another Type I sound board, this time it was the early revision like in the photos in the first post. Thanks to this thread I knew why there were jumpers on the back and proceeded accordingly. The board was from a Phoenix. It was kind of a hair-puller, but it is now fully working and will be going back home.

    1 month later
    #17 6 years ago

    Working on a Type 1 V2 board and thought about this thread and wanted to try and document the differences between the V1 and V2 boards.

    On the V2 board (out of an Algar) the ROM (the SOUND version - no number) was a 2516 and is jumpered the same way as Andrew's photo above. So I'm wondering if that jumpering is for all SOUND1 PROMs and ANY sound ROM file on a 2516 or 2716 EPROM. The note on the schematic for the V2 board says J11, J14, J16 and J18 are for PROM operation and J12, J13, J15 and J17 for ROM operation which is the jumper setting above (and I assume they mean EPROM when they say ROM.)

    This board also has R14 and R23 at 4.7K, the two 10k resistors on the open pads, pins 39 and 40 on the PIA soldered together (a 6821 on this board), pin 34 on the PIA goes to pins 36 and 40 on the CPU and the + side of C5. Pin 35 on the CPU is tied to ground.

    interestingly, looking at the Type 1 v1 schematic from Phoenix, it shows all of the above connections/modifications. The resistor changes are handwritten on the schematic. Go back to Disco Fever and the resistor changes are missing - no 10K resistors and R14 and R23 are listed as 100k. But it shows the PIA connected to pins 36 and 40 of the CPU and the + side of C5. Was the schematic wrong? (Wouldn't be the first error in Williams schematics...) I don't have a v1 board to validate.

    Anyway, looks like once you do the mods to the v1 board it will be the same as a v2 board with the exception of the missing J4 connector and the second fuse on the power input line. And unless pins 39 and 40 on the PIA are not soldered together, there's no need to add jumper wires to a v2 board.

    As for what was wrong on the board I'm repairing, the two buffers (IC8 and IC9) were shot. IC9 was holding pin 16 on the PIA low and IC8 was holding PIA pin 12 high. No sound was playing and there was nothing when you pressed the self-test button. As soon as I cut pin 4 on IC9 the self-test worked on the bench. And when I cut IC8 pin 4 the associated PIA pin started strobing with Leon's ROM. You can guess what I think happened here...

    viperrwk

    #18 6 years ago

    Those input buffers crap out pretty darn often.

    #19 6 years ago

    Driver board was fully functional. Too much of a coincidence to me that the lines on the two buffers that were out matched up with the unkeyed power input connector.

    viperrwk

    #20 6 years ago
    Quoted from viperrwk:

    Driver board was fully functional. Too much of a coincidence to me that the lines on the two buffers that were out matched up with the unkeyed power input connector.
    viperrwk

    hahah... yeah that would do it! That is probably why i find those buffers failed so often, never made that connection. I don think the sound board power connector plug typically has a key in it.

    Hey there! Got a moment?

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