Re: Org-mode as a replacement for Google Reader

["François Pinard" <pinard@iro.umontreal.ca>]

Rainer@krugs.de (Rainer M. Krug) writes:

> Ack?

That comes from ASCII (the first edition of the standard), which had two
control characters (OK, it had more than two control characters, but I'm
only looking at those two!): ACK and NAK, for Acknowledge and Negative
Acknowledge.

At this time, serial communications were often half duplex (only one
side writes at a time), and prone to loosing characters.  RS 232 defined
RTS and CTS (Request to Send and Clear to Send) for implementing half
duplex at the wire level.  When at a higher level, things were differing
depending on if you used asynchronous modems or rarer synchronous modems
(where start bits and stop bits could be spared, so increasing the speed
a tiny bit): asynchronous were using XON and XOFF (Transmission On and
Transmission Off), synchronous were using ACK and NAK.

Do I remember well?  In ASCII 2, XON/XOFF/ACK/NAK were all renamed
DC1/DC2/DC3/DC4 (not necessarily in that order), (DC stands for Data
Control).  Or was it SI and SO (Shift In and Shift Out)?  I'm not sure.
Yet, in any case, ACK and NAK remained in the culture for much longer.

This is while going from ASCII 1 to ASCII 2 that NUL and BEL both
acquired their second "L" :-).

François