(Topic ID: 237259)

Williams Flash doesn't stop after 5 balls played

By uofmer

3 years ago

Topic Heartbeat

Topic Stats

  • 14 posts
  • 5 Pinsiders participating
  • Latest reply 3 years ago by pincoder
  • Topic is favorited by 2 Pinsiders


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    #9 3 years ago

    Stuff like this is frustrating isn't it!

    Have you run my RAM and CMOS tests on it? Perhaps one of the memory addresses doesn't hold a value properly. Those tests check the entire address ranges of each chip. Running the RAM tests is essential too, since the Williams ROMS may simply copy the value in the 5101 to an address in RAM and never look at the 5101 again..

    You could also run the edit_cmos ROM and browse through the actual values in the 5101 chip. Since the chip is 4 bits, an 8 bit number is stored in two consecutive addresses. So for example, the GREEN ROMs expect the Number of Balls per game to be stored in the 5101 at absolute addresses 419=0 and 420=5 (in this case 05 balls per game). As you've already noted, YELLOW ROMs have slightly different absolute addresses, as do the other colors of system ROMS.

    When you boot the edit_cmos ROM, Player 1 display shows the absolute address in decimal, and player 4 display shows the value in that address (also in decimal).

    The addresses before and after 419+420 are used for the related functions in the game setup (High score to date, Replay 1 score, Replay 2 score, etc). I haven't mapped out all of the addresses, but with the editor you can at least browse the values and change them beyond what the Williams ROM will let you.

    Mabye that helps you, maybe not, but you can at least use it to examine the contents of the 5101 and maybe make some sense out of it.

    For those who don't know where to get these test ROMS, they are located here: http://pincoder.reversion.ca

    #11 3 years ago

    What about RAM2? Doesn't system 4 have two RAM chips?

    It would be interesting to map out all the values in the CMOS (and RAM too for that matter). It would be great for debugging their code and learning how it was built. Though the only way to map the RAM though is to put the chips on their own power and keep power to them during a reset/power up cycle and boot an updated edit_cmos ROM. Currently the edit_cmos only maps out the address range of the cmos.

    2 weeks later
    #14 3 years ago

    Nice to see some progress! Did you ever try the edit_cmos again?

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