That’s right. The early cars have a real oil pressure gauge and a real pressure sensor screwed into the block. The change came during 1995 and later cars got a dummy gauge and a simple open/closed pressure switch on the engine.
It’s normal for (real) oil pressure to indicate around 90psi (or 6 kg/cm² for Roadsters) at startup, but it shouldn’t go off the scale. There’s a spring loaded pressure relief valve in the oil pump which should open if the pressure gets too high and dump some oil back into the sump rather than forcing it all though the filter and the engine. From memory that starts to open nominally around 65psi. If it jams shut the pressure could go too high with cold, thick oil at high rpm. If it jams open the pressure could drop too low when warmed through.