This code is generally used on Track 1 of the magnetic card.
Alphanumeric data can also be encoded on magstripes. The second ANSI/ISO data format is ALPHA (alphanumeric) and involves a 7-bit character set with 64 characters. As before, an odd parity bit is added to the required 6 data bits for each of the 64 characters.
- Remember that b0 (bit number 0) is the LSB (least significant bit)!
- The LSB is read FIRST!
- Hexadecimal conversions of the Data Bits are given in parenthesis (xH).
------Data Bits------- Parity
b0 b1 b2 b3 b4 b5 b6 Character Function
0 0 0 0 0 0 1 space (0H) Special
1 0 0 0 0 0 0 ! (1H) "
0 1 0 0 0 0 0 " (2H) "
1 1 0 0 0 0 1 # (3H) "
0 0 1 0 0 0 0 $ (4H) "
1 0 1 0 0 0 1 % (5H) Start Sentinel
0 1 1 0 0 0 1 & (6H) Special
1 1 1 0 0 0 0 ' (7H) "
0 0 0 1 0 0 0 ( (8H) "
1 0 0 1 0 0 1 ) (9H) "
0 1 0 1 0 0 1 * (AH) "
1 1 0 1 0 0 0 + (BH) "
0 0 1 1 0 0 1 , (CH) "
1 0 1 1 0 0 0 - (DH) "
0 1 1 1 0 0 0 . (EH) "
1 1 1 1 0 0 1 / (FH) "
0 0 0 0 1 0 0 0 (10H) Data (numeric)
1 0 0 0 1 0 1 1 (11H) "
0 1 0 0 1 0 1 2 (12H) "
1 1 0 0 1 0 0 3 (13H) "
0 0 1 0 1 0 1 4 (14H) "
1 0 1 0 1 0 0 5 (15H) "
0 1 1 0 1 0 0 6 (16H) "
1 1 1 0 1 0 1 7 (17H) "
0 0 0 1 1 0 1 8 (18H) "
1 0 0 1 1 0 0 9 (19H) "
0 1 0 1 1 0 0 : (1AH) Special
1 1 0 1 1 0 1 ; (1BH) "
0 0 1 1 1 0 0 < (1CH) "
1 0 1 1 1 0 1 = (1DH) "
0 1 1 1 1 0 1 > (1EH) "
1 1 1 1 1 0 0 ? (1FH) End Sentinel
0 0 0 0 0 1 0 @ (20H) Special
1 0 0 0 0 1 1 A (21H) Data (alpha)
0 1 0 0 0 1 1 B (22H) "
1 1 0 0 0 1 0 C (23H) "
0 0 1 0 0 1 1 D (24H) "
1 0 1 0 0 1 0 E (25H) "
0 1 1 0 0 1 0 F (26H) "
1 1 1 0 0 1 1 G (27H) "
0 0 0 1 0 1 1 H (28H) "
1 0 0 1 0 1 0 I (29H) "
0 1 0 1 0 1 0 J (2AH) "
1 1 0 1 0 1 1 K (2BH) "
0 0 1 1 0 1 0 L (2CH) "
1 0 1 1 0 1 1 M (2DH) "
0 1 1 1 0 1 1 N (2EH) "
1 1 1 1 0 1 0 O (2FH) "
0 0 0 0 1 1 1 P (30H) "
1 0 0 0 1 1 0 Q (31H) "
0 1 0 0 1 1 0 R (32H) "
1 1 0 0 1 1 1 S (33H) "
0 0 1 0 1 1 0 T (34H) "
1 0 1 0 1 1 1 U (35H) "
0 1 1 0 1 1 1 V (36H) "
1 1 1 0 1 1 0 W (37H) "
0 0 0 1 1 1 0 X (38H) "
1 0 0 1 1 1 1 Y (39H) "
0 1 0 1 1 1 1 Z (3AH) "
1 1 0 1 1 1 0 [ (3BH) Special
0 0 1 1 1 1 1 \ (3DH) Special
1 0 1 1 1 1 0 ] (3EH) Special
0 1 1 1 1 1 0 ^ (3FH) Field Separator
1 1 1 1 1 1 1 _ (40H) Special
***** 64 Character 7-bit Set *****
* 43 Alphanumeric Data Characters
* 3 Framing/Field Characters
* 18 Control/Special Characters
Error Detection
Two techniques of error detection are used.
Parity
A parity bit is used for each character. The parity bit is defined so that the sum of the ‘one’ bits in the character, including the parity bit, shall be odd.
Longitudinal Redundancy Check (LRC)
The LRC shall appear for each data track. The LRC is calculated using the following method;
The value of each bit in the LRC, excluding the parity bit, is defined such that the total number of ‘one’ bits encoded in the corresponding bit location of all characters in the data track, including the start sentinel, data, end sentinel and LRC character shall be even.
The LRC character’s parity bit is a parity bit for the LRC only, and is encoded as in the section ‘Parity’ shown above.