Article #15691: INTERRUPT HANDLER RULES

 Technical Notes Database

TN691D.txt   INTERRUPT HANDLER RULES
Category   :Pascal
Platform    :All
Product    :Turbo Pascal  4.0+

Description:
Q. What rules should I follow when writing an interrupt handler?
A. The following is a list of rules to keep in mind when writing
   an interrupt handler:

      1. Use GetIntVec and SetIntVec to install/un-install
         interrupt handlers.
      2. Use the interrupt keyword.
      3. Be careful about reentrancy. Don't use any calls to DOS
         or to Turbo Pascal's overlay or heap management routines
         in your interrupt handler.
      4. Interrupt procedures and functions must use the far call
         model (use the {$F+} option).
      5. Be proficient with the BIOS and Assembly language before
         attempting to write an interrupt handler.
      6. Make sure your interrupt handler is not in an overlaid
         unit.
      7. You will want to create an exit procedure to un-install
         the interrupt service routine.


Reference:


7/16/98 4:35:34 PM
 

Last Modified: 01-SEP-99