IIRC the Creed
receiving magnet takes about 20mA to flip it over, but
it=;s quite inductive (4H or so?) If you use what looks like a suitable
voltage, you will find it doen't work, the time constant is simply too
long. Sicne the time constant of a n LR circuit is L/R, you do better by
using a higher voltage (80V is transtional) and a resisotr (around 4k).
Been there, done that....
That part had been taken care of by the previous owner. It had an 80VDC
supply. I just had to do a little extra.
You were lucky... I need to make soemthing for my 7E.....
The Creedd magnet was originalyl mechnically unbiased and needed
double-current signals to operate (current one way for a makr, the other
way for a space). According to the docuemntaiton I have, there was a
bracket and spring to apply mechncial bias to the thing so that single
current signalling could eb used. Did you have that? Or did you do it
properly with +/- 80V?
the Creed
spoke Murray. I still got it printing listings fairly quickly.
Is it strictly Marray code? It's ITA2, certainly, but I thought Murray
code comvined the shifts with spaces, so you had 'letters space' and
'figures space' (and you therefore coudn't print 'RS232C', it would
appera as 'RS 232 C').
Not sure about Murray/Baudot, to be honest. But several character codes
were non-spacing and think the shifts were. Anyway, I modified the
Yes, the shifts are non-specing o na Creed 7, and that's why it;'s not
strictly Murray code.
Baudot, Muray and ITA2 are all different codes. There are similarities,
but the one that is commonly used is ITA2 but it's often mis-named BAudot
or Murray. All are 5 bit.
Baudot code was the code used wit hthe Baudot Quadruplex telegraph systme
which had a 5-key 'chording' keyboard. I seem to remember that the
chracter assignments were made ot make the commonly used characters
easier to send.
Murray is the code used by very old Credd machiens like the Creed 3. The
main differnee is that there is no space character. Instead there are a
pair of characters one of whcih shifts to letters and the other shifts to
figures, both of them also print a space (if you see what I mean).
ITA2 is the code used by Creed 7s and later machines. There is a space
chracter, the shifts only change the state of the selector mechanism, they
do not print a space as well.
-tony
