
================================================================================
     Update Notice           ASYNC.LIB async. i/o package          04/24/84
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        1. The BIOS CTRL-Break interrupt (INT 1B) is now intercepted by 
           the async. routines. This allows CTRL-C to be accepted from 
           the PC keyboard. A local break flag is maintained so that the 
           CTRL-Break event is recorded. The i/o functions, agetc(), 
           aputc(), agets(), aputs(), return an error code of -2 if a 
           CTRL-Break has been entered. This code will be returned on all 
           subsequent function calls unless the local flag is cleared 
           using the clr_brk() function. A function is also provided, 
           test_brk(), which will return zero if the flag is clear and 
           non-zero if the flag is set.


        2. The inbound (receiver) interrupt service now respects the
           DGMODE flag in so far as the Write_Cursor_Address sequence
           is concerned. This allows CTRL-S and CTRL-Q as cursor addresses
           to be handled correctly. The outbound side, Read_Cursor_Address
           is not yet implemented.

         
        3. The return type of agetc() has been changed to (int) from (char)
           and the return type of agets() has been changed to (int) from
           (char *).
         

        4. The initialization function, ainit(), now returns an error code
           of -1 if the transmit baud rate is zero, instead of hanging the
           entire system.

           
        5. Although it should not effect any existing programs, the ainit()
           function now saves the interrupt vectors to be used and aterm()
           restores them. Several other small errors have been fixed which
           should not alter the operation of existing programs.








      

     
     
      

      
      
      







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