On Thu, 15 May 2014, Paul_Koning at Dell.com wrote: First I need to find the exact size of the drive so I can set an RAUSER to it. I can then install RSTS/E *IF* I can get SIMH to boot and install from the RSTS/E V10.1 tape (which I can't get it to do). You mean you have a real drive, and you want to copy it to a disk image file and configure that as an RA file of user-specified size? That will work fine. RSTS can handle disks of any size up to a limit (the RP07 is somewhat below that limit, I d have to dig a bit to find the actual number). If you can just dd the disk to a file, that file should serve. I want to copy an image to a real drive. Alternatively, you can always use a larger disk so long as you don t cross a power of two. RSTS addresses disks by disk clusters which are 16 bit numbers, and the file system layout starts from a given disk cluster size. So if you have a pack with 70k sectors, you can drop it into another pack of 90k sectors but not in one of 130k sectors because that one has a DCS double that of the original. The problem is I have NO IDEA just how big this drive is. Systems tend to disagree about its size...I suppose I can sacrifice the RZ23 for this. If the replacement disk is a fair amount larger, clean ( disk rebuild ) which is RSTS fsck may complain that the free cluster bitmap file is too small. That won t prevent reading but it will make the disk read-only. It gives an initialisation error about it being > a power of 2. paul -- Cory Smelosky http://gewt.net Personal stuff http://gimme-sympathy.org Projects