HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

                         INT 2A,87 - Critical Section

       AH = 87h
       AL = 00  start critical section
          = 01  end critical section

       returns nothing

       - specifies the start or end of a critical section
       - called by PRINT.COM
       - see  Bibliography reference to "Undocumented DOS"

Esc or Alt-X to exit int 2a,87 Home/PgUp/PgDn/End ←↑↓→
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