NAME
    SetSR -- get and/or set processor status register

SYNOPSIS
    oldSR = SetSR(newSR, mask)
    D0            D0     D1

    ULONG SetSR(ULONG, ULONG);

FUNCTION
    This function provides a means of modifying the CPU status register
    in a "safe" way (well, how safe can a function like this be
    anyway?).  This function will only affect the status register bits
    specified in the mask parameter.  The prior content of the entire
    status register is returned.

INPUTS
    newSR - new values for bits specified in the mask.
        All other bits are not effected.
    mask - bits to be changed

RESULTS
    oldSR - the entire status register before new bits

EXAMPLES
    To get the current SR:
        currentSR = SetSR(0,0);
    To change the processor interrupt level to 3:
        oldSR = SetSR($0300,$0700);
    Set processor interrupts back to prior level:
        SetSR(oldSR,$0700);