Hacker News Reader

Comment by genewitch | Hacker News Reader

>This is also how modems used to work

they still do, but they used to too.

All kinds of modems use this kind of scheme as well, PSK is too low-bandwidth for modern needs so everything is QAM these days. DOCSIS specifies I think QAM-256. Inter-datacenter fiber links use "modems" as well.

yes and also soundcard modems: https://i.imgur.com/8mhB4u7.png QAM16 over a PC soundcard into a radio. It's enough bandwidth to stream video between VLC instances. not "slow scan TV", either, fast scan.

Uh, don't try and find this if you're going to use it to pollute the spectrum i am licensed for.

Outside of hobbyists that do it for fun, and maybe some data centers using it as an out-of-band means of access, is anyone still using dial-up?

There might still be credit card terminals using 300 bps Bell 103 (which has a short set-up time due to its lack of training sequences).

1200 bps V.23 and Bell 202 are still in use in radio telemetry applications.

Many aviation fuel pumps in far-out-of-the-way airports use dial-up to authenticate credit cards swiped to pay for the fuel.

Outside of hobbyists that do it for fun, and maybe some data centers using it as an out-of-band means of access, is anyone still using dial-up?

I use it to connect to a Windows machine that runs a large piece of machinery in a remote location.

My dry cleaner's credit card reader, too.

Reply on news.ycombinator.com