Ford Repair: theory of brake operations, abs braking system, ford contour

Question
I have a 1999 Ford Contour SE with a V-6 engine. Mileage is 70k. My VIN number, according to a local Ford dealer, indicates that this car is not equipped with an ABS braking system.

Recently, I had to slam my brakes on as hard as possible. The car stopped but the wheels failed to lock up.
I replaced the brake booster...my mechanic said the master cylinder was okay. After the repairs, my wife drove the car and, by chance, had to slam on the brakes hard. Again, the brakes did not lock up. (FYI, there was no thumping at the brake pedal to indicate ABS action.)

Question: With a non-ABS car, should not the brakeslock up, i.e., all four wheels instantly stop turning, when the driver slams on the brakes?  

Answer
if slammed on hard enough i guess the answer would be yes-but several things could come into play-good quality tires with good traction also a softer tire on dry pavement would not lock up as quick as a cheaper or harder tire would-also is/was brake pedal hard that would be a sign of booster problem-is pedal soft or does it bleed down-did it stop in a normal distance or was it a lot longer than it should have been for the speed-its hard to give accurate diagnosis without checking vehicle myself-i would be really concerned about the stopping distance if it's more than should have been but if normal i wouldn't be concerned.