Magnetic Card Reader Interface Circuit - Panasonic JS-170FR Series Service Manual

2.1.14

Magnetic card reader interface circuit

A magnetic card controller is accommodated in this system, in order to enable readout operation for the magnetic card according
to the Second Track Specification (5 bits, 40 digits, recording density of 75BPI) of the ISO7810 Standard.
When the serial data input from the magnetic card are identified and correctly read out, all the data (start code, end code, check
byte, etc.) read from the serial data are converted into the scan codes of the AT keyboard, and are transmitted to the keyboard
controller.
At that time, the end part of the data is attached with "ENTER" as a scan code.
When data are sent to the keyboard controller, the CLKEN signal and the DATAEN signal are turned to the low level and the
magnetic card controller is disabled in order not to send data to the outside keyboard.
Because of the requirements of the Standard, the card readout speed can cover 8 ~ 150cm/sec.
The CPU reads out scan codes from the keyboard controller, and again converts them into character codes.
For example, a magnetic card with 00012 written as the data may be read out. Then, since the start code (B), the end code (F),
and the check byte (7) are already written in the card, the data come to coincide with the result of the 'B00012F7 Return' input
from the keyboard in terms of operational sequence.
In case of failure in reading out the data from the card, the keyboard controller does not send out any scan code, but the error
LED (red) is lit up.
KBDAT A
KBDCK
RESET #
4 7 K
N0100559V105
4 1
1
P5 2
P1 0
4 0
6 4
P5 3
P1 1
2 0 3 9
RST # P1 2
3 8
P1 3
3 7
P1 4
6 2
3 6
P4 1
P1 5
1 7
I NT 2
1 6
I NT 3
6 0
1 9
I NT 0
P4 3
1 8
I NT 1
3
P5 0
2
P5 1
3 5
P1 6
3 4
P1 7
3 3
P2 0
3 2
P2 1
3 1
P2 2
4 7 K 4 7 K
1 0 0 p
1 0 0 p
M A G O K #
M A G N G #
K B E N A B L E
2-42
CN311
+ 5 V
9
8
Z G ND
7
Z V DD
6
FL MG_ D AT A2
5
T I M I NG2
FL
4
FL C ARD_ I N2
3
FL MG_ D AT A1
2
FL
T I M I NG1
1
CARD_ I N 1
FL