27 Jul
2006
27 Jul
'06
4:20 p.m.
On 7/27/2006 at 5:03 PM der Mouse wrote:
That, at least, *is* standardized. (While far too many
people don't
seem to know it, that's nothing new.) (Even a "2400 baud" modem really
is 2400 baud if you measure it at the correct place, namely, the serial
line interfacing it to the host. This is what you more or less have to
do to make higher-speed modem speeds make any sense anyway.)
(You can count on me to be a good-natured contrarian!)
But is it really? Assuming that we're talking about an asynchronous
connection, there is a grand total of 256 possible valid symbols
transmitted in 10 bit-times (at 8N1, 2400 bits/second). So a modem that
transmits at a 2400 bps rate to its DTE or DCE is really only working at
0.8*2400 or 1920 baud; the start and stop bits convey no information, nor
are they independent symbols.
Sync is a different matter entirelly.
:)
Cheers,
Chuck