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[ih] Impact of history on today's technology [was: why did CC happen at all?]

O my !! THAT was a good test!  ;-)

At 8:12 AM -0400 9/5/14, Bernie Cosell wrote:
>On 4 Sep 2014 at 23:23, John Day wrote:
>>  All Multics terminals were half duplex IBM Selectrix and it was
>>  programmed in PL/1 that used EBCDIC.  But I will defer to Pogran on
>>  this one.
>You're referring to the IBM 2741.  I don't remember a lot but I once knew
>it VERY intimately because I hacked the code into the TIP to make it talk
>over the ARPAnet as if it were a regular full duplex ASCII terminal.
>It was, indeed, a half-duplex, line-at-a-time Selectric.  When you typed
>a line of text and hit RETURN, it locked the keyboard until the other end
>sent something back and unlocked the keyboard.  It had interesting
>characters like circle-C and circle-D.  I think all the documentation on
>that stuff is long gone, alas.  There was some magic sequence you could
>send it that could unlock the keyboard, and so the overall sequence of
>events was something like get line of text, translate to ASCII, send out
>the connection, send the unlock the kbd sequence.   Something comes in
>from the other end: translate to EBCDIC, send the magic sequence to lock
>the keyboard, send the text out.
>I believe that the ultimate test of that software [which wasn't real
>easy] was when I was able to log into TENEX from a 2741..... :o)
>    /Bernie\
>Bernie Cosell                     Fantasy Farm Fibers
>mailto:bernie at fantasyfarm.com     Pearisburg, VA
>     -->  Too many people, too few sheep  <--