Security was pretty much located where it is now, but it was very limited. Think your local county courthouse or a federal building. A very simple metal detector and scanning system to run your bags through.
Put your change and a small pocket knife in the tray and if you don’t set off the metal detector then off you go. Ten seconds max. And there was no requirement to have a boarding pass to go through. If you were following a family member to the gate, you walked through just like them. They also weren’t TSA as that only came about as a result of 9/11. They were basically rent a cops.
The 9/11 hijackers were legally able to get the box cutters on board because the blade was under the permitted size.