Msg: 1935 *Conference*

03-13-92 15:50:08

From: DREW BLANCHAR

To : RICHARD HANSON

Subj: REPLY TO MSG #1904 (BUADOT CODES)

Rick,
  The files you listed are for  Radio TeleTYpe.  We were discussing baudot,
which RTTY uses, but with the idea of using a MDL100 for TDD. 
  
The files you listed 
  RTTY.BA & RTTY.DO use an external modem
  RTTY3.BA & RTTY3.DO are receive only and probably need external modem again
  
The last file you listed, TTY100.BA uses the motor relay of the cassette port!
  
For TDD use, the definition in our book is as follows:
  Signal  110 baud asynchronous
  Originating frequencies:
    Mark    1270 Hz
    Space   1070 Hz
  Answering frequencies
    Mark    2225 Hz
    Space   2025 Hz
  Bits/character:
    11
     1 start
     7 data
     1 Mark parity
     2 stop
  Half Duplex
++++++++++++++++++++++++
The above is for the "ascII" mode.  The book doesn't list all the spec.s for
regular TDD (5-bit baudot?)  but it's probably using the same frequencies as I
can't imagine them building a lot of versatility into the TDD cases.
  
Wait until you try the keyboard at the meeting... really strange like a crank
phone.....3 rows o   keys to cover some 64 characters.
  
KGetting out now as the line noise is gruesome!
-dB