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ADB port
Features
10 kbps serial bus
*This interface supports a keyboard or a mouse.
*Mini DIN
connector
data communication is enabled.
ADB port pin assignments
a)
Table
Signal
Pin
1
ADB
I/O data bus. This is the open collector signal pulled up to
through the 470
2
POWER ON
In Macintosh II family this pin is connected to the pin 4 by the use of
some key on the ADB keyboard until this signal turns on the power.
In other models this pin is not connected.
3
Ground
4
GND
b) ADB port driving procedure
ADB device communicates with Mac through the protocol specified by Apple
computer Inc. which manipulates the
c) ADB port current limitation
Through the bus
current is supplied to ADB device. The total current consumed
not exceed 500
by the device must
(ex.) The current consumed by an ordinary mouse is approx. 20mA.
Figure 1- 29 Mini DIN 4-pin connector
3
connector pin assignments
Functions
register on the main logicboard of a computer.
output
level of ADB signals.
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