Question about modems

Fred Cisin cisin at
Wed Nov 13 14:31:29 CST 2019

On Wed, 13 Nov 2019, Grant Taylor via cctalk wrote:
> Are you sure that the parity stripping (for lack of a better description) was 
> meant to translate things between modems?  I would speculate that it was to 
> transition from serial communications which inherently depend on those 
> settings to TCP connections (raw / cooked / NVT / etc.) which inherently 
> don't use those settings.

But, we thought that modems were FOREVER.  We weren't thinking ahead to 
communication other than POTS (Plain Old Telephone System).
"WOW!  the new modems are 50% faster!  They are close to the theoretical 
maximum for copper wire!"

Parity, stop bits etc. were essential for error detection, ease of 
parsing, and slow physical devices.  A single bit error in a file 
transfer could be disastrous.   But, stuff like commands to the modem 
didn't need much of that, and needed to be able to communicate in spite of 
wrong parameters.  It made sense for a modem to recognize a command, even 
with wrong parity, etc.

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