23 Jan
2014
23 Jan
'14
10:12 p.m.
On Fri, Jan 24, 2014 at 12:47:08AM -0500, Mouse wrote:
Assuming this refers to a Model 15 etc. (e.g. 45 BPS Baudot with 5 bits
per character but they weren't really thinking of them as "bits" so it
was commonly called the "5-level" code), it's actually more like
1.4something
stop bits, since it's just the amount of time it takes the mechanism to finish
its rotation and go back to being stopped against the friction clutch.
It's all analog mechanical stuff (the sampling times are chosen by pegs on
a shaft, like a music box) so there's no reason why the stop period has
to be an exact multiple (or fraction) of anything else.
John Wilson (KC1P)
D Bit
and talking
about 1.5 "bits" in the case of 75 bps 5-level
transmission is just plain insanity.
I'm not sure what's "5-level" about it, but I think "just plain
insanity" is overstating the case; it seems fair to me to consider it a
kind of shorthand for "1.5 bit times".