Take the IBM System/7. Successor to the 1800,
succeeded by the
Series/1. They were *ubiquitous* - one in every telephone exchange in
the USA, I've heard. They even made a special ruggedised version for
shipboard use. Yet they're functionally *extinct*...Unless anyone knows different, no
complete
systems exist. They're extinct, and that's a scandal and a shame.
There exist S/7s in museums in Finland and (I think) Japan. No doubt
there are some still hidden away.
As of 15 years ago, bigger MCI sites had System/88s.
--
Will