FTA: ZX81 emulator for iOS can emulate the infamous wobbly RAM pack and crash the computer when you shake your phone. Emulation level 9999.

Wow. Just....Wow.

That's some way to relive the trauma, add to that at least in my case that the tape was also a hit or miss, wonderful afternoons retyping things in that lovely keyboard. AAAAAAAAAAAAAAAAAAAAARGH!