[GreenKeys] 33 ASR with even parity

[Teletypeparts]

The parity on a 33 is determined by the keyboard.  Early 33's (ALT kybd) tended to have the 8th bit marking or spacing all the time.  

Later keyboards (ESCAPE) can put out even or odd parity or the 8 bit marking or spacing all the time.  You can change the parity by removing or adding slip on connections on the kybd.  You need the manual to tell you how.  The blue covered wiring diagrams book.  

The printer doesnt care about the 8th bit as far as printing correctly.  However, since the tape punch is a slave to the printer if you have it ON it will punch whatever it receives from a computer or tape reader or the kybd.  

Most computer model 33's seem to be even parity, 2 4 6 or 8 bits marking.  Also 20 MA full duplex.  

Most code bar changes are related to auto CR and or auto CR and LF.  Sometimes that is a mystery to me so I tend to leave them as I find them.  

Wayne




-----Original Message-----
From: Don Robert House <packard42 at gmail.com>
To: Stephen M. Jones <smj at cirr.com>
Sent: Wed, Oct 24, 2012 7:33 pm
Subject: Re: 33 ASR with even parity



n 24 Oct 2012, at 7:18 AM, Stephen M. Jones wrote:
Don -
I know that 33 are typically marking parity, but can a 33 produce even  
arity
ithout a codebar change?
Stephen,
Code bar changes are difficult. Everything is spring loaded, which is  
hy my 32 is now a basket case.
ven Wayne Durkee does not want to have to work on the codebars or  
unction levers.
t is easy to work on if you have three hands, but not many of us do.
Only the very oldest Model 33s are non-parity (always marking)  
veryone I ever worked on was even parity.
ou might write to Wayne or Les Veenstra to see what they suggest... 
Teletypeparts at aol.com 
>
Best,
on
P.S.
 could care less about parity... perhaps we could swap typing units..?
ee what the experts say.  DRH

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