A Technical History of Apple's Operating Systems

[Chuck Guzis]

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