TITLE
Apple III Joystick: Apple II Game Incompatibility 

Article ID: 14
Created: 9/21/84
Modified: 7/27/98


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TOPIC 
Some machine language games that use the paddle inputs will not work on the Apple 
III. The hardware for reading the analog inputs is different, and some software 
will not be able to take this into account.



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DISCUSSION 

Also, the joystick ports on the back of the Apple III are arranged such that some 
games won't work properly in Emulation mode. Most joystick oriented games will use 
PDL (0) and PDL (1) for X-Y control. The ports on the Apple III put these signals 
on different connectors. Here are the Apple II Emulation Mode equivalents of the 
signals available on ports A and B.

pin Port A Port B

4 PDL (0) PDL (1)
5 PB1 PB2
8 PDL (2) PDL (3)
9 PB3