The 90s was going to give birth to the most imortant change in the history of the PP SLRs: The digital technique. Kodak was the frontrunner, but had to rely on existing camera houses, primarely Nikons, to wrap in their software. Nikon was
the first camera producer to launch a comercial digital SLR, later to be called DSLR.
DSLR soon was divided into two main categories, the professional full frame with 36x24 mm sensor format, and the half frame based on the film format 24x16 that was introduced
in the 90s, but never really cought on. The system was called Advanced Photo System, consequently the half format DSLRs were called APS-C, the C meaning Classic.
A third format is the Medium Format cameras based on the medium format film cameras, such
as the Pentax 645. These cameras are purely professional and very highly priced.
(Today, some 90% of DSLR sales are APS-C, due to the smaller size and lower price compared to the full frame or medium format cameras AND lenses.)
the wast majority of the cameras sold in the 90s were still film cameras. They were developed to picture machines with programs for this and programs for that. So many options that you could find a program and an AF mode for any situation. Funny to think of,
though, that one will probably work faster in the manual mode, and with better results!
If one knows how to.