AlphaStation 200 NVRAM Problem

Robert Jarratt robert.jarratt at
Sat Apr 23 16:03:13 CDT 2016

>  First of all you might be able to run some SRAM diagnostics yourself,
> 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),
> 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
> machines, they are sweet and they run Linux out of the box. ;)
>   Maciej

Many thanks for all your help today!



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