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Return of pure SETQ but

    Date: 26 March 1980 1141-EST (Wednesday)
    From: Scott.Fahlman at CMU-10A
    Subject: Return of the creature...
    The old bug that gave you an ill mem ref and punted to the monitor when
    you setq T seems to be back on CMUA.  Guess we forgot to pound a wooden
    stake through its heart.  I'll try to look for it someday soon and see if
    it really is the same lossage, but if anyone wants to fix it sooner, feel 
    free.  The offending code was in the handling of "write into read-only
    memory" errors and had to do with the fact that KAs left the PC incremented
    and KLs did not (or vice versa).  Has anyone been messing with this?
I see what the trouble is - not the KL versus KA problem but a bug 
in the way Bob (Kerns) installed the new "WITHOUT-INTERRUPTS" feature.
The macro BNDTRAP, in the dec10 version, inserts two extra instructions
between the label and the offending instruction, thereby thwarting the
attempts of the pure-page-interrupt handler to "recognize" it.  I've
added a "label" argument to BNDTRAP, and modified all the usages in
the *LISP file, but Kerns should think about it too before we reassemble.