In the early '80's, I did some programming with Micro Concurrent Pascal,
on embedded CDP1802 systems. It was really nice to be able to program in
something other than assembly language (a cross-assembler that ran on a
PDP-11 system).
Regarding protections, it didn't have many. I remember spending a day
tracking down a fatal bug with a logic analyzer (emulators were still a
dream in this small company)... another programmer had used an array
subscript out of range and the compiler didn't catch it for some reason.
So in this array defined [0..20], when the typo caused a write to
FOO[60] instead of FOO[20], bad things happened.
Ah, the good old days ;)
-Charles