[wpm]

No you see you just need to buy specially marked boxes of Cap'n Crunch that have a plastic whistle in them that plays the tones for you.

[userbinator]

I wonder how many HN readers still get that reference (and 2600, etc.)

[Y_Y]

I'm merely middle aged, but I've read the hacker lore.

https://en.wikipedia.org/wiki/Blue_box

[hunter2_]

We make use of a service already existing without paying for what could be dirt-cheap if it wasn't run by profiteering gluttons...