The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52.

Despite a wealth of tutorials for setting up and writing code for the ESP8266 WiFi module, there has not been much of anything on programming this cheap wireless module with the Arduino IDE. Finall… ...