PHOTO running on a multi-processor VAX (e.g.  VAX 8800) with
VAX/VMS Version 5.x runs into a problem due to SMP which allows the
subprocess to get MUCH more CPU time then was previously possible
without SMP.  The subprocess generates hangups very rapidly and on a
lightly loaded system it will generate a hangup between the time
"enable_hangups" is turned on and when begin_session posts a
QIOW(IO$_READVBLK) on py_chan.  This causes PHOTO to exit as if the
subprocess had logged out!

     PHOTO has been fixed to issue a QIO instead of QIOW followed by
WAITFR and "enable_hangups" is now turned on after the first QIO to
py_chan in begin_session (used to be turned on in main).  It has been
tested on a VAX 8800 with VAX/VMS Version 5.0-2.  The following
VMS_SHARE file contains a distribution of PHOTO with the fixes described
above.

Mike

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Michael Kimura			Internet:	mnk%draco@hac2arpa.hac.com
Hughes Aircraft Company (RSG)	BITnet:		mnk@draco.hac.com
P.O. Box 92426	  MS: R2/A159	EDEN:		draco::mnk
Los Angeles,  CA  90009		Telephone:	(213) 615-9775
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p.s.  For those of you who don't know about PHOTO, PHOTO copies all of
the Input/Output (IO) that appears on the terminal to a file.  It is
useful for turning in homework assignments, which do most of their IO to
the terminal.  PHOTO requires that you have installed the latest version
of the PY/TW drivers maintained by Kevin Carosso of NRC (kvc@nrc.com or
kvc@ymir.bitnet).