Int 15 Fn 12  - Topview - Send Message - "read" - Get Next Record From Ob  [Q]

   AH = 12h
   BH = 04h
   BL = object
       00h handle is DWORD on top of stack
       mailbox: wait for and get next message
       keyboard: wait for and get pointer to next input buffer
       pointer: wait for and get next message
       02h get next message from mailbox (task's handle on top of stack)
       03h get next message from current task's mailbox
       04h get the next input from keyboard (handle on top of stack)
       05h get the next input from task's default keyboard
       06h wait for input from any object in OBJECTQ (handle on stack)
       07h wait for input from any object in task's default OBJECTQ

Return: STACK: (if objectq) DWORD handle of object with input
          (otherwise)  DWORD number of bytes
               DWORD address

Notes: for a keyboard in keystroke mode, the input buffer is a single byte
     containing the character code as returned by the BIOS; the BIOS scan
     code is available via the STATUS call if the character is zero
   for a keyboard in field mode, the input buffer format is determined
     by the field table header for the window the keyboard is attached to
   keyboard input buffers and mailbox message buffers may be invalidated
     by the next READ, ERASE, CLOSE, or FREE message to the same object

See Also: AH=12h/BH=05h"OBJECT",AH=12h/BH=84h

Format of pointer message:
Offset Size    Description
 00h   WORD    row
 02h   WORD    column
 04h   BYTE    status
       bit 7: set when press/release mode active and button pressed
       bit 6: set when press/release mode active and button released
       bits 7-2: number of clicks-1 if multiple-click mode active
       bits 1,0: button pressed (00=none,01=button1,10=button2)
 05h   BYTE    field number or zero (APILEVEL >= 2.00 only)