F-1
Appendix F
Code 93 Specifications
Code 93 is variable length, continuous, bi-directional, compact code. Code
93 is an alphanumeric bar code which consists of
43 data characters
(
0-
9
,
A-Z
,
$/+%.-
and
Space
),
4 control characters
, and a
unique start/stop
character
. The entire set of 128 ASCII characters is represented in Code 93
using combinations of
control characters
and
data characters
.
The control characters are
,
,
, and
. Pairing these control
characters with normal data characters creates full ASCII 93. It is almost
identical to the pairings for Code 39; Code 39 uses $M to produce a
Carriage Return (ASCII 13) character -- Code 93 uses
M to produce the
Carriage Return.
Code 93's two built-in check digits greatly minimize the possibility of
reader substitution errors. The bar code reader never transmits digits the
check digits. Code 93's Start and Stop characters are also never transmitted.
If you have not decided which bar code type to use for your application and
are considering using Code 93, while we agree that Code 93 is an excellent
code, we believe that Code 128 is generally preferable because:
1. Code
93
does not
have the numeric compression capability
that 128 does, and
2. Code 93 requires pairings to make all Full ASCII
characters while 128 does not.
