Was looking at your listings and saw Silent Service II. It reminded me of something funny.
My brother used to play the original on ZX Spectrum a lot but he got into a habit of leaving it running and expecting me wait for him to come back and finish his game before I could use the computer.
I think I may have let him have his way the first few times, he was the elder brother, but then I'd reset and play what I wanted. When I'd heard him come into the house I'd reset into 48k basic mode and and use the usr* command to create authentic looking system crashes, I even found an address space that made a sound like the engine sound in the game.
I think he must have concluded that the game would crash if left unattended for long periods since I don't remember doing it too many times and I know he'd have gone nuts if he'd had an inkling I was behind it.
usr* launches machine code beginning at the memory address you specify.
