Printout To Check Bottom Pin - Epson FX-80 User Manual

Since computers are faster than printers, there is no significant time
loss in printing a single line of graphics with nine pins. You get nine
dots per line in about the same time as you get eight 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$(nJ CHR$(n
2 ) ;
(Use CHR$(94) if you can't generate the caret symbol (") from your
keyboard.} The d determines the density of the graphics: d set to 0
produces single density; d set to 1 produces double density.
The CHR$(n
1 }
and CHR$(n
2 }
represent the usual width settings, but
each print pattern requires two bytes (instead of one). For example, to
print 60 columns of graphics, you must send 120 data bytes.
Firing nine pins with eight data lines is just a shade more difficult
than firing seven or eight pins. It takes two bytes to define each 9-dot
pin pattern: the first byte determines the pattern of the top eight pins
in the usual way, and only the top bit of the second byte is used. Thus
any second byte of 128 or greater fires the bottom pin of the print
head; anything less does not. Try this sample program:
DELETE l!1'
DELETE 5!1'
DELETE 7!1'
2!1' A$=CHR$(27)+CHR$(94)+CHR$(!I')+CHR$(6!1')+CHR$(!I')
3!1' B$=CHR$(85)+CHR$(!I')+CHR$(42)+CHR$(128)
6!1' LPRINT A$;: FOR X=i TO 3!1': LPRINT B$;: NEXT X
Figure 13·6. Printout to check bottom pin.
Compare this with the densities in Figure 13-4 (this one is single
density). Look closely at Figure 13-6; you'll see that the bottom pin is
printed in every other column.
For fans of 9-Pin Graphics, the (ESC) "0" line spacing is ideal:
it
sets the line spacing to 9172nds of an inch (9 dots).
150