On Wed, Apr 13, 2016 at 12:28 AM, Clem Cole <cl...@ccc.com> wrote: > > Hang on -- BREAK is not in the old USASCII 7 bit map. As explained in > RFC 854, it was a >>key<< on the old Teletype ASR33 (and the ATTEN key on > the IBM 2741). What BREAK did was sent a very long (i.e. 1 second if I > remember correctly) "marking" time signal. >
Huh? Definitely not an ASCII character, but where would an ancient electromechanical device like the ASR-33 have kept this fancy 1 second timing logic? I'm pretty sure that the length of the break is whatever length you could be bothered to hold the key (and thus the line) down. It was only in much later models of terminals that logic got introduced between the BREAK key and the line. Tom
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