Epson MX-70 Manual Do Utilizador

The MX-70 allows any computer to control the firing of its 8 active pins by

simply sending ASCII code numbers between O-255. Conversely, these 256
code numbers are sufficient to control all 8 pins. Multi-line graphics programs
will therefore usually be done with a top-of-line to top-of-line spacing of 8 dots
(8/72”).

As already repeated, many computers, or their printer interface boards, will not
control or pass code numbers greater than 127. These computers can control

only 7 of the 8 active pins in graphics mode. With that common computer
deficiency in mind, the examples in the remaining chapters are limited to 7 dots
per line.

The limitation is not a crippling one. We just have to adjust for it. (The same
field of corn can be harvested by a 2-row corn picker as by a 4-row - it just
takes a little longer.)

Users with ‘superior’ computers can follow right along at our 7 dot clip,
knowing that their computers can drive all 8 pins if desired, but not until we’ve
all finished the course.

Let’s develop a fairly complex graphics picture a step at a time. Everybody
start by typing in these lines:

9 PR 

# l

(Apple)

10 PRINT CHR$ (27) "A" CHR$(7)

20 N=50

30 

PRINT CHR$ 

(27) 

"K" CHR$ (N) CHR$ (0);

TRS-80 Model I:

30 LPRINT CHR$ (27) "K" CHR$ (N) CHR$ (2);

but don’t RUN yet.

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