HP 8753D - Page 408

pin 17
resets the
printer
pins 18-25
are ground
Electrical specications
for TTL
high:
volts(H) =
2.7 volts
(V)
current =
20 microamps
( 
A)
Electrical specications
for TTL
low:
volts(L)
=
0.4
volts
(V)
current
=
0.2
milliamps
(mA)
Figure
6-80.
P
arallel
P
ort
Input
and
Output
Bus
Pin
Locations
in
GPIO
Mode
Application and Operation Concepts 6-141