Flow Chart For a 'for' Loop In Python

  • Context: Python 
  • Thread starter Thread starter Taylor_1989
  • Start date Start date
  • Tags Tags
    Flow Loop Python
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
66 replies · 25K views
The secret of the ASR 33 and ASR 35 teletype machines was some kind of force feedback (I don't know how it worked), that forced you to slow down and type in perfect rhythm with the machine. That did not make fast typing, but it greatly reduced the error rate.

Even today, I wager that I could type with fewer errors with the help of a metronome.
 
on Phys.org
Some vintage history on the teletype

http://www.samhallas.co.uk/repository/telegraph/teletype_story.pdf
And more specifically the asr33

https://en.m.wikipedia.org/wiki/Teletype_Model_33
The heavier key press was due to electromechanical feel of a typewriter. I suspect it may have been an engineering scheme to control the speed of the character bits written to tape or sent over the line as well as typing it on the paper. It’s true though you developed a certain rhythm when typing at about 10 characters per second.
 
Last edited:
Reply
  • Informative
Likes   Reactions: anorlunda
anorlunda said:
The secret of the ASR 33 and ASR 35 teletype machines was some kind of force feedback (I don't know how it worked), that forced you to slow down and type in perfect rhythm with the machine.
A key part of that mechanism was the requirement for deep keystrokes. You had to push the key down about half an inch for it to register - and once one key was down, the next could not be pressed at all until the first key had fully returned to its original position. Since a key would not return to its original position until the cycle had ended, you couldn't type ahead at all.
 
Reply
  • Like
  • Informative
Likes   Reactions: jbriggs444 and anorlunda
WWGD said:
I've tried using Ctrl +C to break infinite loops, to no effect, in Jupyter notebooks . Do you know anything else that would break an infinite loop?

1671582850912.png

https://en.wikipedia.org/wiki/Power_symbol
 
Reply
  • Like
Likes   Reactions: DrJohn and WWGD
WWGD said:
I've tried using Ctrl +C to break infinite loops, to no effect, in Jupyter notebooks . Do you know anything else that would break an infinite loop?
Kernel -> Interrupt, or the ■ button.
 
Reply
  • Like
Likes   Reactions: WWGD
sysprog said:
You could wire the plug-board on a card duplicating machine to allow that, but how would you get, say, an IBM model 29 keypunch machine to do that? It not only doesn't detect which corner is cut, but also as far as I know, it has no capability to read anything on a card, except if you wrap the card around the program drum to be used as a program card, and in that case it could only heed the codes specific to that keypunch machine; not duplicate the card.
Since this thread has been bumped. I'll respond to this.
Here is a link to a 029 instructional video.
The actual mp4 file is here.
The photos below are from frames of that video.
This first image shows the part of the card bed between the punching station (out of frame to the right) and the read station (on the left).
029KeyPunchReadstationB.jpg

I have circled an important part of the card path. It is where a card can be manually fed to the read station.
There's a corresponding slot on the bottom of the card bed that is only barely visible from the cameras viewing angle.
To duplicate a damaged card, feed that damaged source card through that "slot" and feed a blank card to the punching station.
Then, hold down the "DUP" key:
029KeyPunchReadstationD.jpg

029KeyPunchReadstationE.jpg