PDP-11/45 RSTS/E boot problem

[Jon Elson]

On 02/04/2019 04:28 AM, Noel Chiappa via cctalk wrote:
> So I've been helping Fritz look into his -11/45 problem, and things have
> gotten to a point where I'd like to reach out for help, more eyes, etc.
>
>
OH, does this machine have a cache?  We had a /45, and got a 
cache module for it.  It DRAMATICALLY speeded up the system, 
BUT, it caused extremely weird and irreproducible results, 
so we had to take it out.  I never understood the problem, 
but I think it might have been that the cache did not snoop 
DMA transfers.  It ran a single user fine all day, when a 
second user started doing things, both users got crashes and 
garbled data.  This was on RSX-11M.

Jon