November 20, 1994
Hello from Dr. Nemeth to all us graph enthusiasts:
How many of us remember the IBM "braille typewriter?" It
accepted standard-weight and standard-size braille paper of the
kind used by transcribers. The typefaces had braille instead of
print characters on them, and the platten was made of some type
of "soft" material. When a key was pressed, the type struck the
paper with sufficient impact to produce a braille character on
the back of the paper. The carriage escapement was set for the
distance between braille cells instead of the distance between
two pica or elite characters. The paper feed mechanism advanced
the paper one braille line at a time. This machine was quite
popular for a while in offiecs, allowing secretaries and others
to produce Gradd-1 braille for workers or customers who were
blind simply by exercising their normal typing skills. A trained
transcriber could also use the machine to produce Grade-2
braille. The quality of the braille produced was not bad,
although it was not of the quality of braille produced by a
Perkins brailler.
Would it be possible to adapt a 9-pin or 24-pin dot matrix
printer to produce tactile graphs? Replace the standard platten
by one of the kind used by IBM for its braille typewriter.
Remove the ribbon. Then use any standard software program to
produce a graphic file of some sort and send that file to the
prin>er to produce a (tactile) graph in the same way that any
sighted person would produce a graph. the impact of the pins is
sufficient to produce readable copy through 4-ply forms with
carbon paper in between the forms. So the impact should be
sufficient to p
roduce a good raised line with the soft ppatten
behind the paper. A small module would have to be attached to
the software whose purpose it is to reverse the graph in the
left-right dimension so that, when the paper was removed from the
printer and turned "dots-up," the graph would then be properly
oriented. Tim, run that idea by Mike Romeo.
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