With support to both the Arduino firmware and the RomEmulatorTerminal script of a 'download-relay' it is possible to have a 'hands-off download' operation, where the target processor is held in RESET during download. For ROMs intended during startup, this makes firmware development almost as simple as the Arduino environment.

On the image are all relevant components strapped to a carton board and connected to a USB hub. The ROM-EMulator is conencted to the boot-ROM and the target board output is currently the serial port. Even the board is powered via USB. By bridging the RESET switch of the target board with the relay, the processor is halted until the ROM download is completed.

The Arduino sketch and download application script can be found are the ROM Emulator github project page: https://github.com/electrickery/ROM-emulator