Below is an overview of EPSS.
This is from 1977.
I think I got this on 'EPSS Open Day' There are some other documents EPSS with it that I have not scanned yet.
There are also some pictures of EPSS equipment, from the time, on the page here.
|Other related pages from my historical archive (junk pile):
Further Information on this Site
There are also some pictures of EPSS equipment
Other pages about early UK packet switching networks: