27 Jun
2025
27 Jun
'25
1:11 p.m.
A machine that punches the sprocket hole can work with pre-punched tape for one or a few
cycles, but long-term it will punch an elongated hole and drift out of registration. CTI
warns about it in the manual for the 173A “Tape-Ard” I have. (By the way the 173A uses
the same Friden engine that IBM OEMed for the 1620’s 1624 punch.)
Some readers backspace but only as a side effect. For example the Remex stepper motor
based machines. In high speed mode they stop one space past the target then backspace.
Dave Wise
On Jun 27, 2025, at 9:34 AM, Tony Duell via cctalk
<cctalk(a)classiccmp.org> wrote:
On Fri, Jun 27, 2025 at 5:09 PM Frank Leonhardt via cctalk
<cctalk(a)classiccmp.org> wrote:
Thanks - I wasn't sure. I've actually got
a few Teletype 32 and 33s in
my shed but I'm too scared to turn them on after 40 years to check. When
I was coding they were earlier Creed models (mostly). It think one was
an Olivetti, which had style, and an ITT branded 444 that looked like it
The Creed 444 scanned manual I have says 'ITT Creed' on it (and the
address is given as Brighton, not Croydon). I think ITT owned Creed at
that pont
The Creed 444 can also backspace the punch (and will use unpunched tape).
was from the 21st Century (as I imagined
imagined, incorrectly, what the
21st would look like at the time time). I stopped using them even as a
printer when the FX-80 came out :-) (Alas, I only kept the Teletype
Corporation ones, which I kept to scavenge parts).
I seem to recall backed up tape forming a loop rather than rewinding
onto the spool.
Yes, the main use of this facility was to immediately correct a typo
by backspacing the tape and overpunching the incorrect character with
all holes. You didn't need to rewind the tape if you only have 1/10"
of it to bother about.
-tony