I am a licensed electrical engineer who is very passionate in promoting the use of renewable energy to prevent global warming. Me and my wife installed two photovoltaic systems (off-grid and grid-tie) three years ago to reduce the CO2 footprint of our household.
I wrote my first practical program using GW BASIC in the early 90s to obtain the numeric password of a newly acquired but refurbished SL-1 Northern Telecom PABX. Basically, the program connects to the PABX via serial port, inputs a sequence of commands such as logi <CR>, and then expects a response which is the numeric password. The program will then send a value from 0000 to 9999 until an OK response is received from the PABX, in which case it will then stops the iteration and prints the last value which is now the cracked password or passcode if you will.
I can hardly remember the first run of my program in which after a few iteration, the PABX suddenly locked up! That was my first taste of system security and protection going up against me. This was circumvented easily with timing and a few SLEEP in the code.