User.c is used to drive the unimplemented instruction handler (unimp.sa).
Trap vector 11.

Unsupp.c is used to drive the unsupported data/format handler (unsupp.sa).
Trap vector 55.

The unimp handler correctly executes unimplemented trancendentals with normal-
ized operands which are opclass 0 (register to register).  The function fetox
has been tested with the routines which are included.  The makefile will create
the executable however the paths will need to be modified to the specific 
environment of the user.

     Comments which state "REPLACE ..." indicate that to run the code in a real 
system the current opcode must be replaced by the opcode in the comment.
An example of this are the fsave and frestore functions, in order to really
execute these functions one must be in supervisor mode.  The browse code is 
set up to run in user mode with a C call to the handler.  The C call pushes
information on the stack to simulate the integer stack and the fsave stack.
