A92: Divide by Zero Trap

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A92: Divide by Zero Trap


Hey all,

I have some code that forces a divide by zero, apparently to allow you to
fix the denominator.  Here is the best I can come up with to change the
vector for the Divide By Zero error:

...
    move.l    $14,olddivbyzero            ; Store old vector
    bclr.b    #2,$600001                  ; Unprotect memory
    move.l    #_divbyzero,$14             ; Change vector
    bset.b    #2,$600001                  ; Protect memory
...

...
    bclr.b    #2,$600001                  ; Unprotect memory
    move.l    olddivbyzero(pc),$14        ; Restore old vector
    bset.b    #2,$600001                  ; Protect memory
...

...
_divbyzero:
    ; ERROR HANDLE
    rte
...

...
olddivbyzero    dc.l    0
...

This code produces an Illegal Instruction (along with other stuff around
it).  What am I doing wrong?

====
Aaron Hill (mozart@inlink.com)
IRC Nickname on EF-Net: SeracOhw
http://www.inlink.com/~mozart/i3/
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