Pokeing Codes - Epson FX Series User Manual

printing, either by trial and error or by using the hex dumping capabil-
ity of the FX, you can start overcoming them.
Because each computer system deals with ASCII codes differently, it
is impossible to provide solutions for all potential problems in one
appendix. We can, however, point out generic problems and suggest
ways to handle them.
There are four common approaches. First, you may be able to buy
an alternative printer interface card for your system. This is the best
solution for 7-bit system problems. See your computer dealer for
advice about this.
The second approach is to use commercially available software that
is specifically designed to overcome these coding problems. Consult
your computer dealer or computer publications to see if a program for
your computer system is available.
The third approach consists of avoiding the software that is chang-
ing the codes. On most computers you can send each code directly to
the printer. This bypasses the BASIC interpreter and avoids the inter-
face.
Unfortunately, this process is also different for each computer sys-
tem. We'll give the procedure for a couple of systems here; if your
system is not either of them, use the procedure as a model. Consult
your computer's manual to determine if you can do the same on your
system.
A fourth approach is to change the printer driver program in your
system. This requires a knowledge of machine language and of the
way your computer works. If you don't have this knowledge, your
computer dealer may be able to help you or suggest someone who
can.
We show a sample printer driver below (following the examples of
POKEing codes). The idea is to pass the codes as issued by a BASIC
program directly to the FX.

POKEing codes

The TRS-80 Model I version of the CHR$ function does not cor-
rectly pass on the values of
problem as it is very important to the ESCape codes of the FX printers.
0, 10, 11,
and
12.
Zero is a particular
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