It will be used only a subset of the 8051 simplified instructions. Starting this core basics are all structured the architecture and functional blocks. Figure 5. Block diagram of the 8051 ...

Continuous improvements over twenty years led to performance many times greater than envisioned by the 8051’s architects, while retaining compatibility with the original MCS-51 instruction set ...

[Andrew] picked up a handful of these big STC 8051 chips for a song and dance. The problem he has with them is the clunky VB6 programming software that only wants to run on a Windows box.

But what if the Arduino Uno was released in 1980? You’d probably get something like [ElectroBoy]’s 8051-based Arduino Uno. The board itself also has some differences from the original Arduino Uno.