I'm bored, I'm going to do an information dump here
"Legacy" just refers to all non-DishPro equipment. This covers any receivers with 4 digit model numbers, any switches with models starting with the letters "SW", and any lnbfs that
do not have a big black "DP" symbol on them.
The flip side of this is that "DishPro" stuff is all receivers with 3 digit model numbers, all switches with models starting with "DP" (short for DishPro), and all lnbfs that
do have the black "DP" symbol on them.
Some caveats to converting to dishpro:
You cannot mix dishpro lnbfs and switches. They must all be dishpro or all legacy.
Dishpro receivers will work with legacy lnbfs and switches
legacy receivers require an adapter to work with dishpro lnbfs and switches,
except for the dpp44 and dishpro twin lnbf (directly connected)
The dpp44 and dishpro twin lnbf can feed a dual receiver unit (322, 522, 721, 921) with a single cable, using a seperater at the receiver.
The dpp44 and dp34 switches have cascade ports so you can easily daisy chain multiple switches and get more than 4 receivers. A dp34 may be chained off a dpp44, losing the 4th satellite feed.