Program BARCODE.COM
               Copyright (C) 1985 by G. S. Patton

This   is   the   documentation  for  the   CP/M   .COM   program 
"BARCODE.COM",  giving explanation of its purpose,  function, and 
use.   Refer  to the source listing (Turbo Pascal) following  the 
text of this document.

This  program is intended for the public domain,  to be used  for 
other  than commercial purposes only.   All I ask is that  proper 
credit  be given me,  and my copyright notice not be  removed  in 
later modifications.

The  program  was  written  for an  Epson  LX-80  (or  compatible 
printers  with  Epson-code graphics) as the primary  list  device 
lst:.  It will print a standard 3 of 9 barcode for a string of no 
more than 15 characters (due to string length constraints - later 
versions  will  obviate this restriction) in any  selected  print 
density.   Input  string MUST be entered in CAPITAL letters,  and 
must be in the list 0 - 9,  A - Z,  '*',  '-',  '.',  and  space. 
(These are the only characters supported by standard 3 of 9 code.  
Extended versions of the code may support other characters.)

The Epson printer has 4 graphics densities: "K" - low density
                                             "L" - double density
                                             "z" - quad density
                                             "y" - high, 2x speed
"L"  is the only density that produces a usable bar code,  so  is 
installed as the only supported density.

The 3 of 9 barcode is the code specified by the  U.S.  Department 
of  Defense  for  use  in  tracking  products  purchased  on  DOD 
contract, in an attempt to trace costs and avoid $900 hammers and 
$12,000  ashtrays.   It is NOT the code used on retail goods  and 
read  by  grocery store scanners (the Jewel checkout  line  won't 
make sense of it!)

Several parameters are required wnen entering data:  Input string 
(Lower  case will be translated to upper case,  within the listed 
characters),  density  (K or L suggested),  spaces between  codes 
(for aligning on pin-feed labels), and left margin (same reason).  
When  a  code is printed,  it prints the input  string  in  ASCII 
characters  below  it,  so the contents of the code may  be  read 
without a scanner.

Translation of an ASCII string to barcode format is simple.   The 
proper  bit-patterns  for the 3 of 9 code are placed in an  array 
C3of9,  array elements selected by ASCII code.  This is set up by 
declaring  the data type CODES as the values from space  to  "Z", 
and  the array C3of9 as an array,  subscripted as CODES,  entries 
composed of 16 character strings.   A loop selects each character 
in order from the input string (bcr), and the appropriate element 
of array C3of9 concatenated in another string variable bcr2.

Once  the string is translated into equivalent bit  patterns  (#0 
is  a blank dot,  "@" is a dot.),  the printer is initialized for 
graphics  mode,  and  bcr2 is sent to lst:.   The codes  in  bcr2 
translate to pin firings and form the code.

The program may be run in interactive mode by typing
>barcode
at the ccp prompt. The program will prompt for the information it 
needs.  To run the program from the command line, it is necessary 
to  remember one thing when entering parameters:   when  entering 
the  input string,  use underscores (_) between words instead  of 
ASCII spaces.  This prevents the separate words from being parsed 
as parameters,  which will bomb out the program.  The underscores 
will  be  removed by a recursive replacement routine  before  the 
code  is  printed.   The input string may be as long as  desired, 
limited  to 256 characters.   The code will be 16 dots  wide  per 
character  plus  32 dots for stop and start.   The width  of  the 
paper or label will determine the maximum input string size.

Syntax:
>barcode input_string n1 n2 n3
where:
input_string  is  any  string within the limits of 3 of  9  code, 
separated with underscores instead of spaces
n1 is the number of copies desired (for labels)
n2 is the number of lines between copies
n3 is the left margin in spaces.

All parameters are required.  Omission of one or more parameters, 
or using spaces in the input string will bomb the program.

Control-C will break out of the program at any point.