The BBC Micro was (almost) my first home computer (when I was about 8 years old). I can remember spending many a happy afternoon typing in computer programs from magazines only to find they didn't work right. I can also remember playing Elite (which I also played on the Commodore Amiga years later).
Some enterprising chappy has managed to emulate an entire BBC Micro in Javascript, so it runs entirely in your web browser. Aside from highlighting just how far we've come in our computing journey, it's kinda fun writing programs like this again:
10 PRINT CHR$(141) "Dixons is rubbish"
20 PRINT CHR$(141) "Dixons is rubbish"
30 GOTO 10
For something more nostalgic, you can load up the original Elite and try to dock your ship back in the space station. It's a lot harder then I remember ;-)