[cctalk] Alpha EV6 bus coherence

I've been reinventing the wheel quite a bit lately and a couple of new things as well, so I'm glad I was not well-versed in the issues surrounding this machine in the BSD sphere and elsewhere. Some new ideas to help those with this machine: cycle a known-good elsa or permedia with rom disabled through each slot of an empty card-cage. On each swap, unplug the machine from the wall and leave the power switch on for a minute or two, then issue an init at srm. When you run out of slots: This should pattern the entire bus with a calm elsa stamp. There are three digital levels to this coherence problem (at least), and there's the analog one no one seems to have considered as a member of the whole picture. I searched for this above and it was no where. I don't think anyone thought of it. The system trains. I saw it do this recently with the si3114udc card. As the card drifts, the system drifts with it, in sympathy. This drift can become ingrained in the system beyond the digital realm. I think it is totally worthwhile to consider making a card for this purpose using a cheap cpld or mcu. There are already pci projects out there, it could be a snap. I'll look into it, but what it could DO is repeatedly and visciously assert aligned and properly timed data in the same way the 3114 and other misbehaved cards assert mis-skewed data and timing. This, in theory would re-train the entire io subsystem to compliance with the cards whole and healthy stride, normalizing the machine for expansion and deployment. I could really use some feedback. This list has the best there is. Weaponizing init and prefetch and a crash, exploiting the system is good, because it can work, but it isn't the whole fix, just a peek at the mechanisms which can unlock the problem entirely. So today I added an analog or dumb aspect to what has been seen as a monolithic problem. It really is a DUAL problem insofar as BSD is concerned, but for Alpha architecture it is a four-layered problem, as I see it. I lack the targam at this depth, so please forgive my terms: PCI cage physical state (why is this such a stepchild in the process? And red-headed!) PCHIP executing saved bitsieve which was generated by init probe before prefetch is re-asserted (one-boot process). PCI to EV6 bridge, logic and code the training is here, I believe, and incredibly active and intrusive. The SRM is a computer inside the computer. EV6 bus and its side of the divide. The way I see it is shooting through three sets of overlapping chain- link fences. If you are sqare to them and a good shot, you will put your shot through the same hole of the 'grid' and it will land in the appropriate target zone. If you are at an angle, you will land your shot, but it will be dislocated from your planned landing spot. The system is really tolerant to this!, it trains itself..... If I keep hitting the fences, the fences move to accommodate my shot, as though the strikes were physically enough to do that. I think the dec hardware guys wanted to puke when they were told to hang pci off ev6 AND as the only available bus. They hated it with their whole souls. So, the implemented the most rigorous and perfect implementation of the 'standard' they could. It was so good and so rigorous the software guys had to eat the puke they'd made the hardware guys egest. We are dealing with the aftermath of that battle, is my take. I'm just looking at the machine. So if it can fail for bad training, why not try GOOD training? Some of you may remember me. I've been here since 1997 or so? I have no formal education at all. I have 40 years of computing experience and have gotten this far in the project through logic and theory and the output of the framebuffer in various failure modes. One, for example would just look corrupted to a LOT of people, but it looks like a loader for a demo on an 80's 8-bit decompressing its payload. That is informative. I realized that the framebuffer had overflown into main memory and I was seeing the contents of that in this familiar way. That is science, even if it is using in-situ diagnostic tools. Using this as a primary window into the system I've built the theory as expressed here. A smarter person would use expensive tools I don't have, and those have been applied already I'm sure. I'ts been awhile is all. I've been lurking. Please holler! Best, Technoid Mutant Jeffrey S. Worley