Nine-Pin Graphics Mode - Epson FX Series User Manual

You should get another printout of Figure 11-4.
A second time you can make good use of the reassigning code
occurs when you want to change a program in which you have not
concatenated the graphics codes. Using the "?" sequence allows you to
change every instance of your graphics command by entering only
one line.
A third type of use occurs when you want to use a program devel-
oped for a different model of Epson printer. Suppose you have a pro-
gram for circles written for an MX that uses Double-Density-the "L"
variety-and you want to refine it by switching to the one-to-one
aspect ratio. In this case, you would use the following line at the
beginning of your program:
LPRINT CHR$(27)"?L"CHR$(5);
and the FX will do the rest.

Nine-Pin Graphics Mode

Recall that in the last chapter we said that the bottom (zero) pin of
the print head is not normally used in the Graphics Modes. That's
because most microcomputers communicate with parallel-type
peripheral devices using eight data lines (even if they have 16-bit proc-
essors). When the peripheral is a printer, each data line corresponds to
one pin on the print head. Thus each byte sent will fire up to eight
pins.
But the printer has 9 pins available. So how do you fire the ninth pin
with only 8 data lines? In fact, do you really want to bother with just
one extra pin? Well, for such graphics-intensive applications as screen
dumps, printing 9 pins at a time can speed up the process considerably,
For this purpose, the FX has a special 9-Pin Graphics Mode (it won't,
however, work with 7-bit computer systems). In this mode the printer
takes 2 bytes to fire all 9 pins-as shown in Figure 11-5.
Since computers are faster than printers, there is no significant time
loss in printing a single line of graphics with 9 pins. You get 9 dots per
line in about the same time as you get 8 dots in the other Graphics
Modes. Not a bad deal.
The format for entering 9-Pin Graphics Mode is:
LPRINT CHR$(27) "^"CHR$(d)CHR$(n
152
)CHR$(n );
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