Museum of the Game® & International Arcade Museum® Forums
Hello. I am working on a Defender that has a RAM error of some kind. I re-socketed all the 4116s and tested them in the RCT (two bad).
The game plays, but has random "sprinkles". Running the built-in RAM test, I get random failed positions. My best guess is that there is a faulty mux in the data/address path for the RAM, or a component with marginal timing.
But I have the FPGA Catbox and want to use it to diagnose this issue (since the built-in RAM test isn't so helpful). The ROM test passes perfectly, but the RAM test throws a fairly consistent fail. Occasionally, I see a bit pass but nothing to give me much confidence that I configured it correctly, am using it correctly, or it is even working as it should. I also ran the entire Signature Analysis on each DIN and DOUT for all 24 RAM and it checked out. But I can't run Signature Analysis through the muxes (at least as I understand it).
The config I am loading is "DefenderNewLes.ini" because why not. It works for ROMs, Signature Analysis, and IO.
As I said, the game runs aside from the artifacts, so the RAM is mostly working regardless of what the tool is telling me. I definitely have a RAM issue of some kind, but would hope that the FPGA Catbox could report more.
For those FPGA Catbox and WIlliams/Defender users, how do I know which config is correct? What's the difference? Do the RAM tests work? Does the test type make a difference for particular boards, as in works on some but not others? Is there 4116 timing considerations that need to be adjusted for specifically for my boardset?
I want to solve the problem, but I also want to understand more about how to properly use the tool and configs. I think I got the basics...
As always, thanks for the insight.
The game plays, but has random "sprinkles". Running the built-in RAM test, I get random failed positions. My best guess is that there is a faulty mux in the data/address path for the RAM, or a component with marginal timing.
But I have the FPGA Catbox and want to use it to diagnose this issue (since the built-in RAM test isn't so helpful). The ROM test passes perfectly, but the RAM test throws a fairly consistent fail. Occasionally, I see a bit pass but nothing to give me much confidence that I configured it correctly, am using it correctly, or it is even working as it should. I also ran the entire Signature Analysis on each DIN and DOUT for all 24 RAM and it checked out. But I can't run Signature Analysis through the muxes (at least as I understand it).
The config I am loading is "DefenderNewLes.ini" because why not. It works for ROMs, Signature Analysis, and IO.
As I said, the game runs aside from the artifacts, so the RAM is mostly working regardless of what the tool is telling me. I definitely have a RAM issue of some kind, but would hope that the FPGA Catbox could report more.
For those FPGA Catbox and WIlliams/Defender users, how do I know which config is correct? What's the difference? Do the RAM tests work? Does the test type make a difference for particular boards, as in works on some but not others? Is there 4116 timing considerations that need to be adjusted for specifically for my boardset?
I want to solve the problem, but I also want to understand more about how to properly use the tool and configs. I think I got the basics...
As always, thanks for the insight.