From:	CSBVAX::MRGATE!info-vax-request@kl.sri.com@SMTP 13-JAN-1988 12:23
To:	ARISIA::EVERHART
Subj:	RE: BACKUP under VMS 4.6 needs PHY_IO !?!?


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Date: 11 Jan 88 06:00:25 GMT
From: cunyvm!unknown@psuvm.bitnet
Subject: RE: BACKUP under VMS 4.6 needs PHY_IO !?!?
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To: info-vax@kl.sri.com

Five minutes with PATCH can make your /TRACEBACK image /NOTRACEBACK.  I
have done this numerous times to install images originally linked /TRACEBACK.

Use PATCH/ABSOLUTE so that you can access the image header.  The twelve
bytes, usually starting at byte 48 of the image header (30 hex for PATCH)
are transfer addresses.  A normal shareable image linked with /TRACEBACK
has one transfer address, as opposed to /NOTRACEBACK which has none.  Replace
this one (at byte 48) with a zero, and you have it.  There will still be
some extra debugger information at the end of the image file, but it will
be ignored.  You can also reverse the process to debug any system image
linked /NOTRACEBACK.