User's Manual

he 255 is a special number that prevents the computer system from
inserting a CR-LF into the line. Unless, of course, there’s one in your
program.
The extra line feed-CHR$(10)--that accompanies each carriage
return--CHR$(13)--
is
no problem except when you need to use
CHR$(13) in a graphics program. Getting rid of the extra CHR$(10)
is rather complicated. First you open the printer as a random file:
OPEN “LPT1 : ” AS #1
Although this allows you to send any code to the printer, you can no
longer use the LPRINT command. Instead, you must use a PRINT
# 1 command :
PRINT #1,
“Now I can print, anything”
This does allow you to print anything, but it ignores any previous
WIDTH statements.
If you want to print more than 80 characters per line in a
graphics program, you must therefore change your opening
statement to include the appropriate WIDTH statement:
OPEN “LPT1: ” AS #1 : WIDTH $1, 255
And for the programs in this manual, don’t forget to use PRINT #l
wherever we use LPRINT.
This won’t work for those of you who have the original release of
the Disk Operating System (DOS 1.0). It can’t run a printer like a
file. IBM has, however, issued a free update; take a disk to your
dealer to get your copy.
Another printer problem with DOS 1.0 is that it doesn’t send
CHR$(7) to the printer; it just rings the computer’s bell. This has also
been corrected in subsequent versions.
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