[Simh] Simh execution speed improvement - about 45% improvement.

[Marc Chametzky]

> Okay that means SIMH can handle serving up the disks that are currently
> hanging off of my XP1000.  I wasn't sure how large of disks it can currently
> handle.

I had an issue getting 64-bit support to work on my system due to an 
issue with libpcap using STREAMS in 64-bit mode. When I disabled STREAMS 
in the 64-bit libpcap library, networking in the 64-bit VAX binary 
worked properly.

Once I got that resolved, larger (> 2 GB) drives worked in my 
environment (set rq0 rauser=n). However, I ran into some sort of issue 
that I can't explain with a volume that was 20 GB. A bunch of files that 
I added last on the volume all showed up with varying forms of 
corruption when I checked the volume with ANALYZE/DISK/REPAIR. The error 
messages were that the logical block numbers were invalid. All the LBNs 
about which it complained where larger than 4,000,000, making me wonder 
whether something was going wrong in VMS with an RA82 having more than 
some number of blocks.

I want to do some more testing of that to try and narrow down exactly 
when the problem occurs, and maybe understand better how it happened.

--Marc