Bill gets nitpicky with me:
> The originally specified
> maximum data rate of 20 000 bit/s (not baud, which is one change
> of state per second for an analog signal [EIA-232-D* is digital])
> was the limit only for a cable of a certain length (15 m).
I quote from the standard:
"1.3. This standard is applicable for use at data signaling rates in the range from
zero to a nominal upper limit of 20,000 bits per second."
Of course you can run faster with shorter cables (or current external modems would not
work), but that does not change the point I was making. The fact is the standard does
NOT address faster rates and shorter cables anywhere. (Nor, for that matter, does it
have a word about the 9-pin "D" connector and pin assignments that is now ubiquitous
for EIA-232 interfaces.)
In other words, the standard is badly out-of-date with respect to the actual practice.
As to "baud" vs. "bits per second," and "RS" vs. EIA," I am well aware of these
issues, but chose to use the more common terms as neither issue is germane to the
point I was making. (Heck, most engineers could not tell you the difference between
"baud" and "bits per second".)
Jim Elwell
