1 Feb
2025
1 Feb
'25
4:43 p.m.
One used to (in the 1970s) be able to purchase
off-the-shelf "long
haul" modems that converted between EIA signal levels and
current-loop.
Sometimes called "line drivers", because that's not confusingly
overloaded terminology or anything. I was about to say "e.g. Gandalf
LDS family", but iirc those were actually _leased_, not purchased.
If the 25-way DSUB connector bothers you, have a look
at RS-449,
which employs a 37-way (DC37) connector
Some may be amused to remember that the DB/DC/... family of connectors
were known as "D-subminiature" when introduced.
De