From what i remember. San Jose and Minnesota split the players 50-50(although Minnesota got to keep alot of the better players). After that they got to draft players off the other 20 teams(1 player from each team so 10 players per team).
I still remember that my Islanders who didn't make the playoffs had the first player picked int hat draft(Jeff Hackett). Beyond that i remember the 20th pick being Guy Lafleur because Minnesota basically didn't want anybody off of Quebec's roster so they took him because he was retiring.
When the Golden Seals folded(they were in Cleveland by then), they merged with the Minnesota North Stars, so when the Bay Area got the expansion team in 1991(I believe the Barons/Seals owners had a piece of it), they took that half the roster back.