Happy Triple Plus Day - Retro Modem Life Hack

It would seem that there is a day for everything and on October 22 1985 the Hayes modem escape sequence was received its patent.  While it seems silly to patent an escape sequence it is an important bit of history that saw widespread use during the dialup and BBS era.

For those who don't know Hayes modem commands were used to activate a modem from the serial terminal.  For instance, AT would start a command.  ATDT12345551234 would trigger the modem to dial the number 1 (234)555-1234.  If you were still at the modem terminal, once the modem on the other side would connect you could type messages back and forth.

ATA would trigger the modem to answer a call while ATH would hang up the current session.

There was another command, the +++ sequence that would trigger the modem to enter the Data Terminal Ready mode and also would terminate the active connection (in a way resetting the modem)

So, why was the +++ sequence such a big deal?

Well, people found out that transferring a file with the +++ embedded would sometimes trigger modems to automatically hang up.  There were also reports of certain modem-based MUDs where player names with +++ was cause other players to drop carrier when that name was shown on screen.   I think xkcd said it best with the following comic where the punchline was "I hope you learned to sanitize your inputs"

southernamis.com is once again celebrating a bit of retro history with the 40-Year Anniversary of the Three Plus (+++) Salute and maybe one of the coolest modem easter eggs that very few will ever witness again.

Related Web URL: https://www.southernamis.com/group/day/discussion