But what if the Arduino Uno was released in 1980 ... No USB-UART (which also means no USB programming), a different pin layout (Arduino shields likely won’t fit) and more I/Os than the ATmegas ...

The top of the unit looks very similar to the Arduino Uno; the pin layout is identical to that of the Uno, so shields will easily plug in. On the back of the unit is a sticker with a unique ...

His offering uses the Arduino Uno, but there are several other hardware options covered as well. The firmware makes use of the serprog-duino library which was crafted at writing to flash memory chips.