@Caryn Luethe
Many condos from that era use "Gypcrete" on the floor. It is used because its lighter than concrete, has a fire rating, and provides some acoustical benefits. And its cheaper.
It can be patched with many products, including most self-leveling compounds. Cracking in these floors is quite common around here in older condos.
Since laminate flooring "floats", the sub-floor can be somewhat imperfect. Read the install guide for the flooring product you're considering for specific information on flatness, patching, etc.
I'd break free any loose pieces with a scraper or similar and fill in the floor. The most common product is called "Fixall" - it traditionally comes as a powder that you mix with water and apply with a trowel. There are also pre-mixed versions of it (and/or similar products) but they are probably more expensive so it depends on how large of an area you are dealing with.
Basically, if it's loose or sticks above the surface, break it free and fill in the gap left behind. I'd use a strong shop-vac to get a somewhat clean surface prior to filling in the gaps (after chipping away the imperfections).
A laminate floor is pretty "forgiving" meaning it will take up some imperfections better than tile, wood or sheet vinyl.
Preparing the surface is nothing difficult at all.... just spend some time and it will come out fine.
