    FPTRAP(III)                  11/18/73                 FPTRAP(III)

    NAME
         fptrap - floating point interpreter

    SYNOPSIS
         sys  signal; 4; fptrap

    DESCRIPTION
         Fptrap  is  a  simulator  of the 11/45 FP11-B floating point
         unit.  It works by intercepting  illegal  instruction  traps
         and  decoding  and  executing  the  floating point operation
         codes.

    FILES
         In systems with real floating point, there is a fake routine
         in  /lib/liba.a  with this name; when simulation is desired,
         the real version should be put in liba.a

    DIAGNOSTICS
         A break point trap is given when a real illegal  instruction
         trap occurs.

    SEE ALSO
         signal(II), cc(I) (`-f' option)

    BUGS
         Rounding mode is not interpreted.  It's slow.

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