Epson SQ-2000, Руководство по эксплуатации

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Fig. 5-3. User-defined character
Next, you translate the dot pattern you’ve created on paper to a
numeric format so you can send the information to the SQ-2000.
Every dot has an assigned value. Each vertical column (which has
a maximum of 24 dots) is first divided into three groups of eight
dots. Each group of eight dots is represented by one byte, which
consists of eight bits. Hence, one bit represents each dot.
Each bit is a power of two, so that the bits within each byte
have values of 1,2,4,8,16,32,64, and 128. In the vertical column
of dots, the bits are arranged so that the most significant bit
(which has a value of 128) is at the top and the least significant bit
(which has a value of 1) is at the bottom.
Figure 5-4 shows how to use this method to calculate the data
bytes for the first column of our letter A. Each bit that represents
a dot has a value of 1; each bit that represents a space has a value
of 0. To the right of the column the binary numbers are converted
to decimal value.
This last step is merely for convenience. The data you send to
the SQ-2000 can be in any form (binary, decimal, or hexadecimal)
that you can use with your program language. We’ve chosen to
use decimal numbers because the example programs in this
manual are written in BASIC and everyone is familiar with dec-
imals.
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