Reset is used in only HMOS microcontrolers.
WRONG, all uCs need a reset

In CMOS microprocesors there are used only capacitor 10 micro Farads conected to VDD and pin Reset. Resistor is build in microprocessor.
True for SOME derivatives, false for most, both the capacitor size and the built in resistor.
Todays '51 derivatives are very different from each other and global statements such as this are TRULY MISLEADING and usually wrong.

Modern derivatives either has a built-in reset generator (NOT a dumb resistor) or require a supervisor chip for reliable operation.

The RC (regardless of where the resistor is) is truly unreliable when used with modern derivatives.

Erik