[Simh] Slow VMS I/O

[bsupnik at comcast.net]

<snip>
As far as I'm aware (please correct me if I'm wrong), the _flag member
should only ever hold an 8 bit value (even though the member is an int in
size) as defined by the _IO definitions in stdio.h 

On the occasions that the excessive paging/disk accesses occur I have seen
the _flag member hold 0x80XX, where the XX is one of the normal stream
states, to my way of thinking it looks like something might be trying to
reset the _flag member to _IORW but somehow is writing to the upper 8 bits
of the member???!
<snip>

I ran through a complete boot sequence on VMS, and I never saw the _flag member assume any value other than 00XX.  That is, I never saw the 80XX flag set.

I am using Visual Studio C++ 2005... but I also use relatively small disks (RD54's).

Questions for Villy, since Richard has seen the same symptoms with big disks.

1. What size disks are you using?
2. Are they standard disks, or custom size disks?
3. Do you shut VMS down cleanly when you stop simulating?

/Bob Supnik