Experience with the original version of LP3OF9.CO and many requests from
fellow SIGers have caused me to rewrite the program and to produce a 
version that supports Epson printers.  The graphics control codes for the Epson
printers differ so much from those for the Radio Shack machines that it was 
easier to write another version than patch the first one.  All versions of 
LP3OF9.CO are copyrighted, but SIG usersare authorized to copy them forpersonal
use.  Please don't use them for commercial purposes or distribute copies
to non-SIG members without written permission.
     In order to use these programs to print 3-of-9 bar codes, you need a dot-
matrix printer capable of printing around 100 dots per inch and compatible 
with either Radio Shack or Epson control codes.  Radio Shack printers are
placed into the graphics mode by a CHR$(18) and "condensed" resolution is
selected by a CHR$(20).  Epson printers use a CHR$(27);"L" command to go into
"dual density graphics" mode and they require the computer to communicate the
number of graphics bytes to be sent with CHR$(n1);CHR$(n2) where n1 is the LSBY
of the number and n2 is the MSBY, using 16 bit arithmetic.  If you own aprinter
that does not conform to the above requirements, contact me via the SIG or 
EMAIL and I'll be happy to try to make the program work with your machine (I 
love challenges).
     To use the machine language program, first download either LP3OF9.OBJ (for
Radio Shack printers - Checksum=212,739) or EP3OF9.OBJ (for Epson printers -
Checksum=215,515) into a RAM file named "LP3OF9.DO".  These files are Intel
format assembler listings of the machine language programs.  You must then use
HEXLDR.100 (from DL7) or a similar loader to load the M/L into your M100.  All
lines in the listing begin with a colon (":") except the last.  The last two
lines are ":00000000" and"$".  Except for the colons and the "$", the files
should contain only those characters used in hexadecimal notation (0-9 and
A-F). Delete all extraneous characters from the file before you try to load it
with HEXLDR.
     Once you have the machine language program loaded, it is convienient to 
have a BASIC program to load and call it.  Alternatively, you can SAVEM it 
with an Exe address (which is the same as the Top address for these programs), 
and call it from the menu.  A short BASIC program that automatically clears 
the correct amount of RAM and loads the program, then restores the HIMEM value 
to MAXRAM when coding is through is:
          10 CLEAR256,610##
          20 LOADM"LP3OF9"
          30 CALL610##
          40 CLEAR256,MAXRAM
where "##" is 40 for the Radio Shack version and 15 for the Epson version.  I
use this approach over the menu call because it manages the memory better and
it preserves the integrity of the operating system.
     These programs will print out 3-of-9 barcode from text files that contain 
ONLY the characters supported by the 3-of-9 standard.  Any other characters 
will produce an error condition.  The text will automatically be limited to 23
characters per line, and a carriage return will force a new line.  Up to 24 
lines may be printed per 11 inch page.
     LP3OF9 is intended as a demonstration of the barcode capabilities of dot
matrix printers and the Model 100.  It cannot be used by itself to print out
BASIC files, etc., because of its limited character set.  However, you may find
a reason to save the barcode you have printed.  An easy and inexpensive way to
do this is to spray the printed pages with a fixative intended to preserve
charcoal drawings. You can obtain this at art supply stores and many college
campus bookstores.  This treatment prevents the printing from smearing when the
wand is run over it.
     I hope these enhanced versions of LP3OF9 will help SIG members become 
familiar with the barcode system.  Someday we may be able to use it to 
enter programs from the magazines, etc. Just think; no more data lines to type!
                          Merrill Parks
                           [70536,1366]