Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!vsi1!wyse!benefiel
From: benefiel@wyse.wyse.com (Daniel Benefiel xtmp user id dept234)
Newsgroups: comp.sys.ibm.pc.programmer
Subject: BLOCK_MOVE failing on some systems (but never under a debugger)
Keywords: INT 15h, FCN 87h
Message-ID: <2625@wyse.wyse.com>
Date: 5 Mar 90 00:31:27 GMT
Organization: Wyse Technology, San Jose
Lines: 11


I wrote an assembly .COM program to access extended (and primary) memory
using INT 15h BLOCK_MOVE.  On some systems, the INT 15h call fails to do
the transfer when run from the DOS prompt.  On other systems it works fine.
It never fails under any debugger (debug, symdeb, or turbo).

By "fails to transfer" I mean that it transfers nothing (not even garbage).
The failure occurs whether transferring within primary or between primary
and extended.

Any ideas?