Epson LX-80, Руководство по эксплуатации

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p ro gram to decide which dots are filled in and which are left bl a n k.
I t is often better to use squared graph paper to make up the de sign,
and th e n transfer the dot pattern to the program. In order to do this
it i s n e c e ssary to understand how the print head transfers the dot s to
th e p a per.
Print Head
Th e gr a phic s mode on the LX-80 is quite different from the text
mode s . Instead of sending codes for letters and printing functi ons,
th e c o d e s y ou send are ones that print a pattern of dots in a colum n .
N o n e of th e predefined characters or symbols in the printer ' s m em-
o r y i s us e d. Your program controls exactly where each d ot is
pr i n te d , column by column and line by line.
Th e co lumns are defined by the row of pins on the print head. In the
s t a nd a rd g r a phics mode it uses only the top eight pins on the print
hea d beca u se the computer uses eight data lines to communi cate
wi th th e printer. Each of the top eight pins of the print head corres-
po nd s to o n e of the data lines. There is also a graphics mode which
a ll ows a ll nine pins of the head to be used.
Wh en yo u want to print figures more than eight dots high , it is
n ecessa r y t o print on a new line , advancing the paper and prin ting
a n o th er lin e, just as you would with text . To keep the print head
from l eav in g gaps between the graphics lines as it does betw ee n the
tex t l i n es, the line spacing must be adjusted to eliminate thi s gap.
W h en th e lin e ~pacing is properly adjusted, the LX-80 print s f inely
de t ai l e d g r a phics images that give no indication that they a r e m ade
up of separa te lines , each no more than 1/8 of an inch high .
T o e n s ur e t h e proper alignment of dots in figures that use mo re than
o n e l i n e, t h e LX-80 abandons the bidirectional printing it u ses for
d ra ft t ex t . Instead it prints from left to right only in graphics m ode.
It i s n o t n ec e s sary to fill the whole page or even an entire lin e with
yo u r gr a phics figures . However, before you send the data c orres -
p o nd i ng t o the columns of the pattern, you must tell the printer how
mu c h d a t a to expect . This information is part of the graphic s com -
m a nd .