@hap,

after starting the ARB SArgon 2.5 you have to click on [New Game] before you can start to play (without it not even the board is usable).
In MessChess the plugin does this job by sending a send_input(":IN.0", 0x80, 1) to the device.
Can this also be automated for MessExtra, i.e. without using a plugin?

I've searched through the MAME drivers and found commands for sending a value to an ioport, so I tried the following command in machine_reset()
of the ave_arb driver: ioport("IN.0")->write(1,0x80)
It compiled without errors, but unfortunately it doesn't seem to do anything!?

Is this command wrong? Is there any other command to simulate this keypress (i.e. to activate this ioport) in the driver, or is this not possible at all?

Regards,
Franz