Solutions For Seven-Bit Systems - Epson FX-80 User Manual

50 IF B>9 THEN B=B - 7
60 T=ASC(MID$(B$,P + 1, l)) - 48
70 IF T>9 THEN T=T-7
80 POKE A,B*l6 + T
90 A=A+1
100 NEXT P
110 POKE 16422, 187
120 POKE 16423, 64
This driver will also work on the TRS-80 Model III-with one
change in line
you use this program, you can kiss problems with radical codes good-
bye.

Solutions for Seven-Bit Systems

The BASIC language on some computers can only send seven bits
to the printer at one time, even though the machine language may be
able to send eight. (The Apple II Plus is a case in point.) On such
computers, the CHR$ function cannot send the entire range of ASCII
codes (0 - 255) to the printer; it can send only the lower half (0 - 127).
To find out whether your system is an 8-bit system, capable of
generating all 256 ASCII codes, enter this simple test:
10 FOR X=160 TO 254
20 LPRINT CHR$(X);
30 NEXT X
If you get Italic characters when you RUN this, you are using an 8-bit
system.
If you have a 7-bit system, you need to understand what happens to
the control codes you send. The FX automatically interprets these
codes the way your system sends them-as the lower half of the
range. There is something you can do when you want to send the
upper half (128 - 255): have your program convert all codes outside of
the active range to their equivalent in the upper half by adding 128 to
them.
The problems that are associated with 7-bit systems include:
Tabs can't be set in both code ranges (to avoid problem codes).
Limitations on width in Graphics Mode.
Inability to use the top pin for Graphics Mode.
10:
change 32E837 to D3FB. That's all there is to it. If
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