Connect over serial with a 9-pin VGA.
ls /dev/tty to find
screen /dev/tty.usbserial-1130 9600 cs8 -cstopb -parenb -ixoff- disconnect 9-pin connector and reconnect
- push button
- power on
- button off
- send connection message
- power off
- push button
- power on
- button off
+++
ATA
AT&V