[GreenKeys] Fwd: Current Loop

[Chris Elmquist]

Apologies, I sent a link to the wrong manual.  Try this one instead,

http://vt100.net/mirror/harte/Altair/MITS_Altair_88-sio_Serial_IO_Card_Manual_Version2.pdf

This is _really_ the SIO2...  and on page 30 (48 in the PDF) it's got
wiring diagrams for connection to a TTY33.

Chris

On Monday (07/20/2009 at 08:44PM -0500), Chris Elmquist wrote:
> I think he needs to have a model C 88-SIO board, which has support for 20mA
> loop.  The A model is RS232 and then he'll need a converter.  The manual
> for the 88-SIO_2 is here,
> 
> http://vt100.net/mirror/harte/Altair/MITS%2088sio_2%20Serial%20Card.pdf
> 
> and on page 6 it discusses how to connect to a teletype.
> 
> 
> I think I saw his posting on the Stockley Altair replica site and I
> tried to reply but I think my posting got lost.
> 
> Chris N0JCF
> 
> On Monday (07/20/2009 at 07:44PM -0400), Teletypeparts at aol.com wrote:
> > 
> > Hey Guys, 
> >  
> > I am forwarding a message I got from Tom Lake who has a 33 he got from  me. 
> >  Can anybody help him with the problem he is having hooking up the 33  to 
> > his Altair?  The 33 is wired for full duplex (4 wire) and he can make  the 33 
> > receive work OK, but I am not familiar with the Altair hook up as he  
> > describes it.  
> >  
> > Thanks,
> >  
> > Wayne
> > KB1FDW
> > 
> > 
> > From: thomas.lake at srmt-nsn.gov
> > To:  Teletypeparts at aol.com
> > Sent: 7/20/2009 2:04:56 P.M. Eastern Standard  Time
> > Subj: Current Loop
> > 
> > 
> > Hi, Wayne!
> > 
> > Remember me?  I  bough a Teletype from you a while back.
> > 
> > It's still working fine with my  PC but now I'd like to use it with
> > my old Altair 2SIO serial interface board  which is supposed to handle
> > 20 mA Current Loop OK.  The problem is the  teletype prints from the 
> > computer
> > but won't input to the computer.  I  know the TTY is good because, as I 
> > said,
> > I can use it with my computer with  no problem for input and output.
> > Is this a problem with active/passive  loops?  Is there a way to change the 
> > TTY
> > to allow one or the other  on both TX and RX?  I don't see a way to change 
> > the
> > 2SIO board to do  that so I'd like to adjust the TTY if possible.
> > Do you have any other  ideas?
> > 
> > Thanks for any help you may be able to give.
> > 
> > Tom Lake
> >  
> > **************An Excellent Credit Score is 750. See Yours in Just 2 Easy 
> > Steps! 
> > (http://pr.atwola.com/promoclk/100126575x1221323041x1201367261/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=62&bcd=Jul
> > yExcfooterNO62)
> > ______________________________________________________________
> > GreenKeys mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:GreenKeys at mailman.qth.net
> > 
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> 
> -- 
> Chris Elmquist
> 
> ______________________________________________________________
> GreenKeys mailing list
> Home: http://mailman.qth.net/mailman/listinfo/greenkeys
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:GreenKeys at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

-- 
Chris Elmquist