Installing XXDP and RT-11 to RL02

As I've still not figured out why VTServer isn't working with the RL02 drives, I've been experimenting with different methods of transfering data from a PC to the PDP-11. I've tried simply copying disk images under BSD on SIMH using dd, but this hasn't yet resulted in a working boot disk. Depending on which device under /dev I write to, I get either a "filesystem read-only" error or a corrupt image on the target device. I've therefore been using a variation of the trick I used to get the last bits of 2.11 BSD installed to set up RT-11 v5.3 and a full XXDP 2.5 installation. The basic process is to install a system to RD53 on SIMH, transfer the resulting disk image to a real RD53 using VTServer, then use this installation to create an RL02 copy.

Although this doesn't work for all operating systems, both RT-11 and XXDP lend themselves to this process as they support both source (RDxx) and target (RL0x) disks and contain all the tools required to create a new bootable copy of a running system. Due to their size, they're also suited to running from RL02 disks, which are also of course much easier to swap out than an MFM unit. An added bonus is that when copying at file level, as opposed to copying raw images, you can take account of any bad blocks you may have on the target device.

For XXDP, the process is pretty much the same as that I used before to copy from an emulated TU58 to an RL02, the only difference being the device names and the number of files copied. Installing RT-11 is not much different and is described in the Installation Guide, which can be found amongst a wealth of RT-11 documentation at the University of Queensland . The installation media itself (an RL02 image) is one of the software kits for SIMH . When this is booted, you're asked if you'd like to do an automatic installation. This is only useful if you're installing to another RL02 disk, so enter "NO" to boot the installation disk directly. You can then format the destination disk, copy the files over and write the boot block using something like this:

.INIT DU0:

DU0:/Initialize; Are you sure? Y

.SQUEEZE/OUTPUT:DU0: DL0:

.COPY/BOOT DU0:RT11XM.SYS DU0:

At this point, it's a good idea to copy any other software you may want to run later to the new image, as this can then all be transfered in one go. The resulting disk image was, thanks to SQUEEZE which consolidates as it copies, only about 2.5MB and easily transfered using VTServer. After booting from the RD53, copying to RL02 is just as simple, although you ought to use INIT/BADBLOCKS or INIT/REPLACE to take care of any bad blocks. As the above process also copies the protection from the original media, you'll want to unprotect the files on the last copy you make. After booting from the new media, just run:

.UNPROTECT/SYSTEM *.*

 Files unprotected:

DK:SWAP.SYS

DK:RT11AI.SYS

DK:RT11PI.SYS

DK:RT11BL.SYS

DK:RT11SJ.SYS

[a whole list of files scrolls by...]

DK:V5USER.TXT

DK:V5NOTE.TXT

DK:CUSTOM.TXT

DK:CONSOL.MAC

DK:NITEST.MAC

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