CGA monitors may not be an amazing technological advance these days, but they can generally be found very cheaply. Additionally, they have a DB-9 connector and work off of TTL ranges (0-5VDC) makin… ...

The Arduino Zero uses an Atmel ARM Cortex-M0+ for 256kB of Flash and 32k of RAM. The board supports Atmel’s Embedded Debugger, finally giving the smaller Arduino boards debugging support.