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Comment by bluGill | Hacker News Reader

In the end owning a printer is only worth it because getting to an office supply store is such a pain when I need to print something.

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Same.

It's a 5-15 minute drive for me to get to the print shop. It's near food options that I eat at somewhat regularly, so I could just tack it on to a trip to dinner, but still...

I'd rather spend the $150 once and never need to go to the print shop ever, though I did need to recently to send a fax because the DMV is still living in the 90s.

Side note...my smartphone is...well...a phone, in addition to being a computer. Why the hell can't smartphones send faxes?

Scan with random app, send with any of the various pdf-to-fax services?

As for the why... faxes operate over the legacy network using an acoustically coupled modem.

Software modems used to be common and how many people connected to the internet. They didn't work as well as hardware modems but they did work. there is no reason a modern smartphone which has a much more powerful CPU couldn't do a software fax (smartphones also have a GPU which is possibly even better for this type of processing). IIRC the fax protocol is pretty dumb/simple so it seems like it shouldn't even be difficult - though I don't need a fax often enough to bother to try.

My point is the fax protocol is analog. How do you do analog over 4G/5G? Any solution is going to involve some sort of central server.

It would work the exact same way I can call an analog phone line from my phone.

At some point, yes, the digital signal from my phone gets converted to an analog signal to be sent over traditional telephone wires. My phone just has to produce the right noise for a receiving fax machine to understand it once the noise is converted to an analog signal.

> Scan with random app, send with any of the various pdf-to-fax services?

Looked into it...so many of them want you to subscribe or have a stupid pricing scheme.

> As for the why... faxes operate over the legacy network using an acoustically coupled modem.

There's nothing special about a fax connection. It's just a telephone line (which my phone has). The "modem" part could easily be done in software. All it has to do is synthesize the right noise on the line.

The issue is that the typical compression used on cellular voice calls completely destroys the modem signal you've just synthesized.

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