PDP-11 disk image question

Zane Healy healyzh at avanthar.com
Sat Feb 16 11:35:18 CST 2019


> On Feb 16, 2019, at 9:10 AM, Lyle Bickley via cctalk <cctalk at classiccmp.org> wrote:
> 
> Bill,
> 
> On Sat, 16 Feb 2019 13:55:10 +0000
> Bill Gunshannon via cctalk <cctalk at classiccmp.org> wrote:
> 
>> So, I used SIMH to do an install of a complete OS on
>> an RA81 disk.  I would like to  move this to a real disk
>> and try it on a real PDP-11.  Is there a way to do this
>> using dd on a BSD machine?  I tried but it created a
>> non bootable system.  Well, actually, it starts to boot
>> but then fails very early in the startup process.  I used
>> "dd if=filename of=raw-device bs=1024".  Could it be that
>> the block size needs to be something else?
>> 
>> I know that VTServer and PDPGUI can move disk images but
>> it would take a week at 9600 baud and I think very little
>> likelihood of it ever completing successfully.
>> 
>> bill
> 
> In order to do this easily, I have SCSI controllers (and disks) on my
> two primary PDP-11 systems (11/34 and 11/83).
> 
> 1. I copy the image file I want on a "native" drive using a PC w/SCSI
> and Linux to a SCSI disk (or removable media) using "dd".
> 
> 2. I move that drive/media to the SCSI "chain" on a PDP-11.
> 
> 3. I use RT-11 to move the image from the SCSI drive/media to the
> "native" HDD.
> 
> Its a bit cumbersome, but I used this method for years and it hasn't
> failed me yet ;)

Like Lyle I have SCSI controllers on my PDP-11/73, and my PDP-11/44.  I’ve actually installed RT-11 and RSX-11M+ from CD-R.  There is another option, and I’ve used this with RL01’s and RL02’s.  With those, I’ve used a MicroVAX II or MicroVAX 3 and VAX/VMS.  I used to have a  dedicated MicroVAX 3 setup with RA73 drives for this.  I still have the hardware, but it hasn’t been used since 2000.  If you have a way to hook the RA81 up to a VAX, I think that would be an option as well.

Zane





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