Epson LX-80, Operating Manual

Page: 91 / 193

If you only wan t to fi re one pin, send the ASCII code cor r esp o n ding
to its number . T o fir e more than one pin at the same time , add up
the numbers corre sponding to th e pins you wi s h to fire and send the
ASCII code of th e s um to the printer . For example if y ou want to
fire just the top pin se nd AS C II code 128 . To fir e just the bott om pin
send ASCII code 1 . To fir e both the top and bottom pin in th e same
column, send A SCII cod e 129.
By adding the a ppr o pri a t e number s tog e ther , y ou can fir e any com-
bination of pins. Fi g ure 9 - 2 s how s y ou thre e example s of how to
calculate the n umb e r th a t w ill fir e a p a rticular pattern of p ins.
128
•
1 28
1280 1280
640
64.
64 640
320
320
320
16
•
1 6
160
160
80
8.
8
80
40
40
4.
4
2 .
2
2.
2
20
1 .
1
1 0
•
1
0
1 47
0
14
0
5
not used
not used
not used
Figure
9 - 2.
Ca l c ul ati n g n umb ers f or p i n pa t t erns
With this number in g sys t e m a n y co mbin a t i on o f th e e i g ht p ins adds
up to a unique deci m a l num be r b e tw ee n 0 and 2 5 5. A lth ough you
use a decimal num b er, t o de t e rmin e which pin s a r e to b e fir ed, since
you send the ASC II co d e cor r es ponding to th e numb e r , th e printer
receives a binary nu m b er .
Having covered t h e p r in c ipl es of E pson graphic s, it is t i m e to pro-
duce some programs a nd th e n ex pl o r e th e mor e compl ex com-
mands .
First Graph ics Program
Rather than pro du ce a co mpl ex lin e of graph i c s th e fir s t graphics
program prints th e sa m e p a tt e rn 40 time s. In this wa y you can see a
clear result from inputting co d e t o on e c olumn wherea s ju s t printing
one column wo uld r e quir e a micro s cope to determ i ne wh e th er the
pattern was cor r ec t .