Re: Brings back memories
Right, killer sequences... "ZZZZZ as well as certain control sequences", you mention... Well, there was this Hayes patent on inserting a "two second pause" between parts of a command to make their modems not hang up on the (otherwise valid) +++ATH0\n sequence. Of course, most manufacturers did license this, and several manufacturers found ways not to... But I do remember seeing a modem that could be pushed to hang up this way. Very fun for us BBS (ab)users! :)