I'm reading Namir Shammas' book "TP6; OOP" and he links Object Pascal
to the Mac and Wirth's Pascal.
It is fair to say that Borland Turbo Pascal had a rapid development
from Control Data 1976 to the PC of 1990. I don't see any
discontinuities.
Free Pascal, derived from Turbo Pascal, is still my tool of choice.
But I still use 1.0.10 on SuSE Linux 8.1 .