> First of all you might be able to run some SRAM diagnostics yourself, either > from the console (if it has a tool for this; at worst you could poke at it > manually with deposit/examine commands, but the complicated flashbus > access protocol will make it a tedious task unless there is a way to script it)
I have been trying to work out how to do that very thing. I don't think there is quite enough info in the technical manual. > or > from the OS (can't help how to do this from VMS; under Linux you could > mmap(2) /dev/mem at the right address and then poke at it with a little > program doing the right dance to get the flashbus access protocol right), to > see if it shows any symptoms of misbehaviour. If necessary I should be able to install linux, but still, working out the address doesn't seem trivial. > > To experiment with DROM you might be able to find a DIP-to-PLCC socket > adapter, pinouts for ROMs are pretty standard I believe. I have ordered an adapter so I can read the ROM. Would be good, as you suggest, to read someone else's to compare... > A ROM emulator > might help too if you can get your hands on one, second-hand units are not > exactly expensive nowadays as they went out of favour it would seem. > > Overall, hard to say which failure case would be better (or worse). It looks to > me like at this point you have several options to proceed with. > > Good luck with your investigation and recovery! I wish I had one of these > machines, they are sweet and they run Linux out of the box. ;) > > Maciej Many thanks for all your help today! Regards Rob