[GreenKeys] Model 15 timing

Wed, 12 Feb 2003 15:06:07 -0800

Almost all machines perform a complete rotation, stop and latch 
clutches during the stop pulse to get ready for the next character. 
The 37 has two stop clutches so that the character is printed in one 
half of a revolution.  It also does not go back to "home" after each 
character, it goes from one to the next, to the next.  To accomplish 
this it not only has a "front plate" but also a "side plate" for the 
extra positioning work.  So even though it is printing at 150 wpm the 
shaft speed is slower than the 35 or 28 at 100 wpm.

7.42 unit code is correct for most 5 level machines.  It is often 
referred to as one and a half.

Don

>OK, So the clutches stop things every cycle, even thought the 
>machine is running at max speed?
>Where does the 7.42 come from? I though it was 7.5 bits?
>7.00 code is just one stop bit? At max speed, How would it get back 
>in sync when it gets out?
>Manually typing with a 7.00 code machine would likely work just 
>fine, because I'm sure I add hundreds of milliseconds to each stop 
>bit. :)
>
>I will look for the gear part numbers and see what I can find.
>
>Dave, WW8S
>
>----- Original Message -----
>From: [email protected]
>Date: Wed, 12 Feb 2003 14:06:33 -0600 (CST)
>To: david freeman <[email protected]>
>Subject: Re: [GreenKeys] Model 15 timing
>
>>  As Don says, send the gear part numbers and maybe some of us can tell
>>  what the book says about them.
>>
>>  You might have a 50 baud gear set, as some M15s were used in Telex
>>  service.  I don't have a handy reference for the main shaft speed, but
>>  it is faster than 368 RPM because the selector stops between characters.
>>  The keyboard shaft is what runs at 368 OPM in a machine with 7.42 unit
>>  code.  Now you might have gears for a keyboard with a different cam.
>>  Western Union liked to run 7.00 code to get something like 65 WPM.
>>
>>
>
>--
>__________________________________________________________
>Sign-up for your own FREE Personalized E-mail at Mail.com
>http://www.mail.com/?sr=signup
>
>_______________________________________________
>GreenKeys mailing list
>[email protected]
>http://mailman.qth.net/mailman/listinfo/greenkeys

-- 
--------------------------------------------------------
Don Robert House
North American Data Communications Museum
URL: http://www.nadcomm.org
Computer Museum of America
URL: http://www.computer-museum.org