To be honest I am a little confused by your response. In my VAX 780 emulation I am using RQ as an RA92. This has a real-world size of 1.5GB and capac=1505766912 while dwidth=16. In this case capac is giving me the value I would expect. In the PDP11 emulation I am using RP as an RP04, which I believe is about 85MB. In this case I get capac=43980288 and dwidth=16. So capac in this case would appear to be half the size in bytes, I can multiply it by 2 because of the 16-bit word length to get the right size in bytes, but if I do so then I would calculate a size for the RA92 of 3GB, because it too has a dwidth of 16, so I would get double the actual size.
What am I missing here? Thanks Rob > -----Original Message----- > From: [email protected] [mailto:simh-boun...@trailing- > edge.com] On Behalf Of Bob Supnik > Sent: 30 May 2010 19:46 > To: [email protected] > Subject: [Simh] Byte capacity > > The same way SCP does it: > > (dptr->dwidth + CHAR_BIT - 1) / CHAR_BIT > > You can just use 7 and 8 for constants, if you prefer. > > /Bob > > On 5/30/2010 12:00 PM, [email protected] wrote: > > Send Simh mailing list submissions to > > [email protected] > > > > To subscribe or unsubscribe via the World Wide Web, visit > > http://mailman.trailing-edge.com/mailman/listinfo/simh > > or, via email, send a message with subject or body 'help' to > > [email protected] > > > > You can reach the person managing the list at > > [email protected] > > > > When replying, please edit your Subject line so it is more specific > > than "Re: Contents of Simh digest..." > > > > > > Today's Topics: > > > > 1. Simulated disk size (Rob Jarratt) > > > > > > --------------------------------------------------------------------- > - > > > > Message: 1 > > Date: Sat, 29 May 2010 23:41:00 +0100 > > From: "Rob Jarratt"<[email protected]> > > Subject: [Simh] Simulated disk size > > To:<[email protected]> > > Message-ID:<01bf01caff80$0615cff0$12416f...@[email protected]> > > Content-Type: text/plain; charset="us-ascii" > > > > I have recently discovered that my difference disk code does not work > well > > with all simulated disks. I had tested it with the RQ disks in the > VAX 780 > > emulation. Recently I have had occasion to try the PDP 11 simulation > and I > > have discovered that my code does not work with RP disks. This is > because I > > rely on the capac field in the sim_unit structure. From what I can > tell this > > field is the number of bytes for an RQ disk, but the number of 16-bit > words > > for an RP. Is there a consistent way for me to discover the size of a > > simulated disk in bytes? > > > > Regards > > > > Rob > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: http://mailman.trailing- > edge.com/pipermail/simh/attachments/20100529/10afb6ba/attachment- > 0001.html > > > > ------------------------------ > > > > _______________________________________________ > > Simh mailing list > > [email protected] > > http://mailman.trailing-edge.com/mailman/listinfo/simh > > > > End of Simh Digest, Vol 78, Issue 15 > > ************************************ > > > > > _______________________________________________ > Simh mailing list > [email protected] > http://mailman.trailing-edge.com/mailman/listinfo/simh _______________________________________________ Simh mailing list [email protected] http://mailman.trailing-edge.com/mailman/listinfo/simh
