Installing Ultrix 4.4 on a DECstation 5000 Model 240

[Ethan Dicks]

On Wed, Nov 17, 2010 at 6:14 PM, Charles Dickman <chd at chdickman.com> wrote:
> On Wed, Nov 17, 2010 at 2:51 PM, Rob Jarratt
> <robert.jarratt at ntlworld.com> wrote:
>>       It is failing at the stage of detecting the disks with
>> an "invalid block size" error.
>>
>> I am using a CR-506 CD-ROM drive and the disks I have are RZ56 and RZ57.
>
> Could this be an issue with the CD-ROM not supporting 512byte blocks?
> I know that microVAXen need this to install VMS, perhaps this is true
> with Ultrix also.
>
> With some drives you have to set a jumper to force it to 512byte blocks.

Some drives (like the older ones I have) use a jumper to force
512-bytes-per-block-mode at power-on, others _support_ 512-byte-mode,
but you have to send them a request to do so.  Old SPARCstations don't
know to send the request; newer SPARCstations know how and can install
from with either type of drive.

That having been said, I don't know which type the CR-506 is, but it
should be easy to establish.

-ethan