Microvax II won't boot, hardware error?

Message: 5 Date: Thu, 25 Oct 2012 08:17:50 -0400 From: Rick Murphy <rick at rickmurphy.net> To: <cctech at classiccmp.org> Subject: Re: Microvax II won't boot, hardware error? Message-ID: <201210251217.q9PCHosl030262 at rickmurphy.net> Content-Type: text/plain; charset="us-ascii"; format=flowed At 06:39 PM 10/24/2012, Kevin Reynolds wrote: Here's what that machine check stack frame means: 803AF1E8 0000000C 12 bytes of parameters 803AF1EC 00000082 Machine check code = Write bus error, virtual address 803AF1F0 7FF38058 Virtual address 803AF1F4 02000002 Internal CPU state. 803AF1F8 00001534 PC 803AF1FC 03C00001 PSL It seems that you are getting hard memory write faults on the stack. Maybe something is hanging up the Q-bus, or you have failing memory. If you have diagnostics, running a memory test for a while may get you somewhere. Otherwise, I'd look into trying to pinpoint the problem by removing memory modules and see if the system becomes more stable (assuming you have multiple memory cards, of course). -Rick Memory is NOT on the Q-bus, it has it's own dedicated bus on the C-D connector rows (how many slots are memory only in the CD rows depends on the specific backplane.) Possibly you might have a Q-bus board in a memory-only slot, that is certainly something to check. Otherwise, you may have a bad memory card, a bad or dirty slot, or possibly a bad CPU board. Hmm, I've never seen this error, but I think if a peripheral board is bad, it does not cause a machine check, but maybe I've never had the specific error. Can you tell what the physical address was? or, at this point, might virtual=physical? If so, is 7FF3xxxx in the Q-bus I/O space? Jon