[Damian Peckett] has implemented an Apple ][, its 6502 processor, and a cassette port, all on an Arduino Uno. If that wasn’t enough, he also uses a PS/2 keyboard for input and outputs analog VGA.

But even after eliminating the Uno from your selection, you'll still be left with a wide array of Arduino boards to choose ... and D12. The PWM output pins on the two boards also differ, with ...

The humble ATmega328 microcontroller, usually packaged as an Arduino Uno, is the gateway drug for ... efficient class-E RF power amplifier with PWM for about 5W of output power.