Adapter Not Detected
     The BIOS in the PS/2 may not acknowledge the presence of a joystick adapter installed in the system (this problem is not related to the board installation/configuration provided through the POS by the IBM setup utilities).  Therefore, any game that checks the BIOS equipment list may report that there is no joystick installed.  To correct this problem, execute the program GPA-INST.EXE  This program will update the BIOS equipment list to include the GPA-1000.

Related Info
From Peter
  The gameport is a typical example for ISA-style arbitrated passive MCA cards. The joystick base-I/O port is already defined in the BIOS and once the hardware addresses this - and only this port - it is recognized by the BIOS and used. No IRQ, no DMA, no RAM or ROM area occupied - just plain polled I/O ... from the definition of the MCA this card is a "I/O slave" and it not even needs an ADF. 

   The better cards however supply ADFs and come with own card-ID - to avoid problems during automatic configuration and to define the used resources. But there are joystick cards for MCA that just "plug in" and need no ADF. Installed a few of them in 1988 or so for some customers who *claimed* it were for a serious purpose (but no one believed that ...).

Mouse Override under W9x?
Fred Mau wondered:
   >If one has a Joystick plugged into the game port under Windows 9x, will it ALSO override the mouse cursor and buttons during normal computer operation, or will it only operate when it's invoked by a specific game or program ?

Peter Fired Back:
   The joystick does not override the mouse. It is only used when the software is configured for the use with a joystick.

  And please keep in mind that "joystick" on these adapter cards does not mean one of these silly switch-triggered beasts but one with potentiometers (like on RC-car controls). See "sound" on Louis' page and look for the schematic diagram of the Audiovation joy-port. There's a small graphic on how the joystick is wired internally.

Port ENABLE  Select ENABLE to activate the GPA-1000.  Select DISABLE  to effectively remove the GPA-1000 from the system."
          ENABLE  (io 0201H - 0201H) or DISABLE