Dec 282017
Lets IBM jrs and TRS-80's to act as teletypes for the deaf.
File TDD.ZIP from The Programmer’s Corner in
Category Science and Education
Lets IBM jrs and TRS-80’s to act as teletypes for the deaf.
File Name File Size Zip Size Zip Type
NOTES.DOC 1810 888 deflated
P.BAT 128 66 deflated
PA.BAT 256 119 deflated
TD2.DOC 2688 1278 deflated
TDD54.ASM 24064 8469 deflated
TDD54.DOC 26240 8328 deflated
TDD54.EXE 3200 1492 deflated

Download File TDD.ZIP Here

Contents of the NOTES.DOC file

(Added by Harvey Scali)

The batch files included in this library were written to run on
my 256k PC JR, but the concept is applicable for any PC if there
is a ramdisk facility. The purpose of the batch file is to keep
everything in memory so that the tdd program need not be reaccesed
from disk each time a phone call is to be made.The P.BAT files is first
executed from the A disk. It then writes the TDD files to the C Disk
along with another BAT file which then controls the running and
re-running of the TDD program from the C Disk. If you don't want
to use these BAT files just erase them and execute TDD54 from
your A disk.

Also, about the interface, for the PC Jr IBM sells a cassette
cable that has the 3 required plugs, so there is no need to make one.

Further, if you are making your own interface, in order to use the
auto-dial facility of the program you have to wire from the on/off
switch in the speaker-phone to the small plug on the cassette cable.
To locate the proper wiring points, hold the speaker-phone board so
that the foil side is facing towards you, and the on/off switch is
pointed upwards. You will see where the switch is connected to the
board: there are 6 terminal points as follows:




The points indicated by an 'X' are the ones to which you connect the
wires that go to the smallest of the 3 plugs on the ibm cable. Be
CAREFUL not to solder any of the nearby points accidently (as I did)!

(These notes added by Harvey Scali, from instructions given to me by
John Spalding - leave me a msg on HEX (301) 593-7033 if you
need clarification on these notes).

 December 28, 2017  Add comments

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