[Simh] VAX and disk device size oddness

[Mark Pizzolato - Info Comm]

On Friday, February 15, 2013 at 7:41 AM, Lennert Van Alboom wrote:
> On Fri, Feb 15, 2013 at 03:51:08PM +0100, Johnny Billquist wrote:
> > Hi.
> >
> > On 2013-02-15 14:32, Lennert Van Alboom wrote:
> > >Hello,
> > >
> > >
> > >I just started playing with a simh vax again. Built the 3.9 vax
> > >binary (on linux/powerpc), and it works fine.
> > >
> > >Odd thing though: I cannot use RAUSER, it seems. I tried the following
> line:
> > >
> > >SET RQ1 RAUSER=20000
> > >
> > >Which should result in a 20GB disk. No dice though: simh claims
> > >"invalid parameter". I tried lowering the size to 10000, 5000, ... no
> difference.
> > >
> > >I then tried replacing the RAUSER by RA92, which should be supported
> > >and have a ~8GB size. This was accepted. However, from the OS (VMS
> > >7.3), after an INIT/ERASE the disk reports 2940951 blocks which is
> > >somewhat under 1.5GB. The
> > >RQ0 RA90 reports the expected 2376153 blocks or somewhat under
> 1.2GB.
> >
> > Don't know where you got that an RA92 would be 8G. It is really just
> > 1.4G. The largest RA drives ever manufactured were the RA73 at 2G.
> 
> Aha - so what I'm seeing is normal then. Not sure where I got the 8GB
> number - iirc from some usenet post. Guess I should check numbers before
> taking them for granted.
> 
> > >Now, the host OS is on a PPC G4, which means a 32bit kernel. Is this
> > >what is causing this? If yes, can I work around it? I'd prefer
> > >something bigger than 1.5GB :-)
> >
> > RAUSER is what you need. I don't think simh even knows of the RA73...
> 
> I would, but that doesn't give me decent size disks... after some trial & error
> it seems like I'm hitting the 2GB barrier. RAUSER=2047 works, RAUSER=2048
> fails. I don't suppose I can work around this on a 32bit host system, or can I?

A 32bit kernel should not be a limiting factor since MANY 32bit OS environments have been capable of disk file access to files larger than 2GB for a very long time.

You fail to get specific about what OS you are actually using, since several are available which will run on that hardware?

Please spell out exactly how you built the simulator you are working with as well?

If changes need to be made to naturally support your platform, we can readily add these to the code base.  Please pickup the latest code from https://github.com/simh/simh/archive/master.zip and let me know the answers to the above questions and if you still have a problem if you merely:


	$ mkdir simh
	$ cd simh
	$ unzip ../master.zip
	$ make vax

I'm looking forward to your feedback.

- Mark Pizzolato