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MORE GRAPHICS PROGRAMMING TIPS
At the end of this chapter, we’ll discuss two modes that the
printer offers to help you solve potential graphics problems.
A redefining code allows you to change the density for graphics
programs that use one of the four alternate codes. The 9-pin
graphics mode allows you to use all nine pins on each line and
thus speed up screen dumps.
Table 7-4
More praphics commands
Function Control code
Redefine the graphics mode < ESC > “?” n0 nl
9-pin graphics <ESC> “,,” n0 nl n2 ml m2 . . .
n Redefining alternate graphics codes
Your printer provides a command to redefine one of the
alternate graphics modes - K, L, Y, or Z - so that it represents
any other of the seven graphics modes. The command is
<ESC> “?” n0 nl, where n0 is one of the four ietters, “K”,
“L”, “Y”, or “Z”, and nl is one of the numbers used with the
<ESC> “*” command, 0 to 6. There are several instances
in which you may use this sequence.
The first occurs if you have written a program to be printed
in one graphics mode and now want to print it in another. If
you have used concatenation to store your graphics command
in one short character string, that will not be difficult. You
can simply change the mode number or alternate code in the
definition of the character string.
Another instance where you can make good use of the re-
detining code is when you want to change a program in which
you have not concatenated the graphics codes. Using the
< ESC > “?” sequence allows you to change every instance
of your graphics command by entering only one line.
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H 9-pin graphics mode
In the early part of this chapter, we said that the bottom
pin of the print head is not normally used in the graphics modes.
That’s because most computers communicate with parallel-type
peripheral devices using eight data lines. When the peripheral
. .