Mod Ms Pacman PCB to run on 64kb EPROMS and not old 2532 to play a Perfect pacman

  1. 12-15-2020, 09:41 PM
    Hi Sean

    I will consider the options you have listed but I am in situation where there are no more known contactable information for
    arcade specialist here in South Africa anymore that do work on "Arcade doc" level. There used to be many but either they did stop
    doing repairs because the demand for it here is low. Arcade hobby cabinets are manufactured using "pandora" boxes.

    Two arcade specialist who do know a contact or two do want to provide the person name, probably scared, they loose business.
    Nevertheless I will try again do some reaching our locally.

    I did bought an old crappy pacman clone from someone where the pacman is a "ladybug" that PCB I can salvage some 2114 RAM and 74LS367 for test mode logical gate... but the wiring that were done on that test PCB do show that the person was well versed
    reading a schematic to link 4 wires from a 2764 to other sources on the copper traces.

    The main factor sending PCB via postal is the cost just for shipping is about $100 USD+ to get the PCB on the other side of the Atlantic ocean. If one add the repair price it could add up. The great idea to pay for the fix by donating one of the defunct" PCB is an idea. PCB were bought from MikesArcade, tested, perfect clean, refurbished in mint condition. So I accidentally forgot cabinet is running on the same main power as the power drill I am using enhancing the cabinet. Power surge did something....So I think the error is small but where do I find the real error is exactly as you mention not an easy task.

    It make sense having a PCB fixed such a way by someone so that the PCB can stood the test of time as you mentioned below.

    Thanks for your very good tips.

    In the meantime I will see if I can fix the PCB when I will receive pacman capkit, new pacman & msapcman roms, ram chips from the USA about end of January or February 2021 (next year) when my brother will visit our family coming from the USA.(He is a resident and lives in USA).

    Francois du Toit
    streaming mspacman normal and turbo speed at:

    Francois du Toit
  2. 12-16-2020, 03:56 PM
    Hi Francois,
    If a power surge took out your game, then the ROMs are probably not your problem first. Check out Doc's recent videos about Breakout board fix. He had to replace almost all the chips lol. You should check your power board and the transformer thoroughly. Make sure you have proper voltages. This game is 40 years old. Hope you will do the cap kit on the power supply and the monitor as well. I would also recommend replacing the fuse box and resolder the header pins.

    Your brother is coming to visit you in about a month and a half. What if you sent the boards to Sean (I'm Mark, Arcade Doc is Sean;) ), he fixes them and sends them to your brother in the US and then he brings them with him when he comes for a visit? He already has the chips in the US, so he can send them to Sean as well. Shipping the boards in the US should be around $20-25 max, so you can save some money that way as well. Well, just an idea while you still have some little time. You should at least contact Sean to keep your options open. Arcade repair is his second job, so he may not answer right away. Other option is to wait for your brother, try the ROMs and the cap kit and then he could take it back with him, if the boards still don't work. The second option makes you lose more time. No matter what you chose, at least try contacting him to keep this option open. You don't want to try to contact him at the last moment. I highly recommend you replace all the sockets on the boards, so that's another reason to send the boards in (keep that in mind). Just that Hakko desoldering gun costs $270 new. Using a cheap solder puller is a serious task when you have to replace many sockets.

    Did you try to verify the ROMs you have? I think you still might be able to read them with your cheap programmer, just not write to them. You can dump the data and compare CRCs with a good rom file.
    Last edited by omega175; 12-17-2020 at 07:58 AM.
    Thanks francoisadt thanked this post
  3. 12-19-2020, 02:49 PM
    Quote Originally Posted by francoisadt View Post
    Yes I have thought about doing an adaptor for my EPROM programmer that can write a 2764. The problem is that 2532 EPROMS need a 25V pulse to "write enable" whereas the 2764 only 5V. So the circuit in the EPROM Programmer only caters for 5V feed.


    I am not able to view the circuit designs at the bottom of the article, can you? (I got timeout from the webpage)

    No, I can't either. It looks like they've lost their image host.

    Have you successfully read and written one of those new EPROMs with your programmer?
  4. 12-26-2020, 03:25 AM
    The EPROMs are 8KBs
  5. 01-02-2021, 01:14 PM
    Quote Originally Posted by finlay31 View Post
    The EPROMs are 8KBs
    That is correct. Double the size and 28pin instead of 24pin.
    The mapping between the two different layouts I have posted in an
    earlier post.
    streaming mspacman normal and turbo speed at:

    Francois du Toit
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