78 Delta User’s Manual
the boxes. If we tried to print overlapping dots, Delta’s print head
would have to slow down and back up to print both dots-not very
efficient! To avoid this inefficiency, Delta will not allow you to
define a character like Figure 7-6. (Actually, you can define it, but
when it prints, Delta will leave out the overlapping dots, so that it
would print like Figure 7-5.)
m, m, m, m, m5 m, m, m, nww-h, 1
2
4
8 WRONG!
16
32
64
Total
Figure 7-6. Dots cannot overlap; those in immediately adjacent “half columns
will be ignored when the character is printed.
Add up each column of dots
Now it’s time to give our creative side a break and get down to
some basic arithmetic. That’s where the numbers down the left
side of the grid come in. Notice that there is a number for each
row of dots and that each number is twice the previous number.
By making these numbers powers of two we can take any combi-
nation of dots in a vertical column and assign them a unique
value. Some examples will make this clearer. As shown in Figure
7-7, if we add the numbers for the dots that print in a column, the
sum will be a number in the range of 0 to 127. Each number from
O-127 represents a unique combination of dots.
So add up the values of the dots in each column using this
system. This way it takes one number to describe each column of
dots. In Figure 7-8 we’ve shown our grid with the sums of the
columns filled in across the bottom (see if these agree with your
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