> >> i think 5x7 is used because
   >

Back in 1973, at Georgia Tech (USA), a buddy and I wrote programs in Fortran
and Algol that
would print a banner on computer printout paper.  We'd submit the programs
on Hollerith card decks
with the Data cards being the message we wanted printed.  Each letter in the
banner would
print in a 5x7 matrix using the same letter for each dot.  So, the letter A
would print with
letter "A"s, the B would print with the letter "B", etc.  Like this:

(view in fixed font)

  A    BBBB
 A A   B   B
A   A  B   B
AAAAA  BBBB
A   A  B   B
A   A  B   B
A   A  BBBB



Anyway, we experimented with different matrix sizes and discovered that a
5x7 matrix seemed
to fit all letters (upper case only) pretty well so that's what we used.
Having an odd number of
rows was good so you could have a line in the middle of the character for
"A", "B", "E" etc.
BTW, the computers we used were Univac 1108 and Burroughs B-5700.

Carey Fisher

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