Ralph Mowery wrote:


I worked in industry and had a lot of older instruments. Some were a
real pain to work on and the factory did not support them any more. We,
as the repair shop, told management they were just going to have to bite
the bullet and update them.
Well, this is modular signal processing modules, we have a wall of probably
400 of them of all different types. The companies that made this stuff in
the 1970s are mostly out of the business, and most of the modules we have
have no currently manufactured replacement. So, we don't have a lot of
choice. Some modules have been so troublesome we have, indeed, retired
them.

Jon