That's not how it worked.
Before free agency, you had "Plan A" players and "Plan B" players. The plan A guys were protected; you couldn't get them no matter what. But each team could only protect something like 30 players.
Plan B guys were essentially free agents, where other teams could make offers to them. But the team itself chose which guys were Plan A or Plan B.
The teams had a lot more leverage as to player salaries because the players couldn't go anywhere. Once you were with a team, if you wanted to leave and they wanted you to stay, the best you could hope for was to hold out and force a trade.
No salary cap WILL NOT make the game more like the 80's. It will make it more like baseball, where you pay 7 million bucks for your third string backup OG.