You can see the article and the illustration that goes with it. David Ondrik took the picture of the Tack Tiles that appeared on the cover of TPJ #15.
See also the Perl source and data tables to the Braille encoder I got more-or-less working, using just regular expression string replacement. The article was a study in algorithmics more than anything else, so I don't expect that anyone'd take my code and use it as the basis for a new braille encoder -- since tried-and-true encoders already exist. But you never know who it might prove interesting or useful to!
See also a chart from my handout at the conference, a List of Characters in American Literary Braille.