The 8051 was an 8-bit Harvard-architecture microcontroller first put out by Intel in 1980.  They’ve since discontinued that line, but it lives on in the low-cost STC8 family of chips, which ...
In the maker world, it’s the Arduino and ESP32 lines that get the lion’s share of attention. However, you can do fantastic things with PIC chips, too, if you put the dev time ...