OSBYTE &98

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OSBYTE &98 (152) - Examine Buffer Status

   X=buffer number
   On exit C=0 Y=offset from address held at &FA to the next byte to get
           C=1 buffer empty
   (Acorn MOS 2.00)
   The Y register actually contains the next value,not just an offset as with
   the earlier OS.
   Note Interrupts should be disabled during this call to ensure the interrupt
        routine doesn't alter the buffer while you're reading it
        This OSByte doesn't actually remove the byte
        No range checking is performed on the buffer number and nonexistant
        buffer numbers have undefined results

See Also

Jgharston 22:09, 26 May 2009 (UTC)