A: PCAX = A pulse
B: PCBX = B pulse
C: +5V = Supply
D: *PCAX = A pulse complement
E: *PCBX = B " "
F: PCZX = Marker pulse
G: *PCZX = Marker compl.
H: OG = shield
J: +5V
K: +5V
L:
M:
N: OV
P: OV
R: OH1X = Thermal switch 1
S: OH2X = Thermal switch 2
T: OV

R & S are the thermal sensor.

Al.