From: nowhere@never.at   
      
   On 20/11/2023 18:45, Scott Lurndal wrote:   
   ...   
      
   > INT 15h Func C2h is the Mouse interface for PS/2 and subsequent systems.   
      
   subsequent 16 bit BIOS may emulate PS/2 from USB.   
      
   > According to _The Undocumented PC_, the subfunction 07h sets the mouse   
   > handler address (a far pointer).   The BIOS interrupt handler will call   
   > the handler whenever a new mouse report is made.   
      
   > If the INT call fails, carry will be set.   
      
   YES, olde RBIL say it more detailed:   
      
   INT 15 - SYSTEM - POINTING DEVICE BIOS INTERFACE (PS) - SET DEVICE   
   HANDLER ADDR   
   	AX = C207h   
   	ES:BX -> FAR user device handler or 0000h:0000h to cancel   
   Return: CF set on error   
   	    AH = status (see #00522)   
   Note:	when the subroutine is called, it is passed the following values   
   on the stack;   
   the handler should return with a FAR return without popping the stack:   
   		WORD 1: status (see #00525)   
   		WORD 2: X data (high byte = 00h)   
   		WORD 3: Y data (high byte = 00h)   
   		WORD 4: 0000h   
   SeeAlso: INT 33/AX=000Ch   
      
   Bitfields for pointing device status:   
   Bit(s)	Description	(Table 00525)   
     15-8	reserved (0)   
     7	Y data overflowed   
     6	X data overflowed   
     5	Y data is negative   
     4	X data is negative   
     3	reserved (1)   
     2	reserved (0)   
     1	right button pressed   
     0	left button pressed   
   __   
   wolfgang   
      
   --- SoupGate-Win32 v1.05   
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