The Amiga chip registers that handle the  controller port  i/o are listed
below.

   joy0dat  ($dff00a)  counter for digital (mouse) input (port 1)
   joy1dat  ($dff00c)  counter for digital (mouse) input (port 2)
   ciaapra  ($bfe001)  input and output for pin 6 (port 1 & 2 fire buttons)
   pot0dat  ($dff012)  counter for proportional input (port 1)
   pot1dat  ($dff014)  counter for proportional input (port 2)
   potgo    ($dff034)  write proportional pin values and start counters
   potgor   ($dff016)  read proportional pin values
   bplcon0  ($dff100)  bit 3  enables the light pen  latch
   vposr    ($dff004)  read  light pen position  (high order bits)
   vhposr   ($dff006)  read  light pen position  (low order bits)