MicroVax II update

Josh Dersch derschjo at gmail.com
Fri Aug 5 22:40:27 CDT 2016

On Fri, Aug 5, 2016 at 7:44 PM, Douglas Taylor <dj.taylor4 at comcast.net>

> On 8/5/2016 4:48 PM, derschjo at gmail.com wrote:
>> On Aug 5, 2016, at 1:42 PM, Douglas Taylor <dj.taylor4 at comcast.net>
>>> wrote:
>>> Progress on getting the MVII up and running:
>>> I ordered the SCSI2SD adapter and it has come in, the plan is to use it
>>> as the system disk on the MVII.
>>> The hobbyist VMS PAKS have arrived and I was able to download the VMS
>>> 7.3 iso, not sure what I can do with it since I think it must be burned to
>>> a 512 byte sector CD.
>> Burn it to a CD.  Shouldn't be anything complex here.
> I was able to expand the compressed file using 7-Zip and generate the iso
> image.  However, when I tried to burn the iso to a CD Win7 reported that
> 'The selected disk image file is not valid'.  Not sure what all that means,
> but anyway VMS can't handle a CD with 2048 block size so I stopped fooling
> around with that.

The built-in ISO burning support in Win7 is garbage, use something like
ImgBurn or the like to do the job.

>> I asked if the PAKS were good for older versions of VMS, like 5.5, and
>>> was told yes they were.  We'll see about that.
>>> The Hobbyist VMS CD I had for VMS 7.2 was found and I was able to get
>>> the old Toshiba CD drive to work on the MV 4000 using a CQD 223A.  How can
>>> I create an image of these CD's on the VAX 4000 that I could use in an
>>> emulator?
>>> I wasn't able to get the UC07 to see the CDROM because of a bad SCSI
>>> cable, I had hoped to format the SCSI2SD using the UC07
>> Keep in mind that the SCSI2SD can pretend to be a CD-ROM, and can emulate
>> up to 4 SCSI devices at one go.  No need to futz with a real drive if you
>> don't want to...
>> Josh
> Yes, I believe that is the way to proceed.  Let the SCSI2SD be a couple of
> drives, one for installing the software onto and another to contain the
> installation CD image.  At this point it is kind of a 'chicken and the egg'
> thing for me, the only scsi interface I have is on the VAX.  I don't have
> one on the PC where the VMS image is, so I'm perplexed as to how I get the
> software installation CD onto the SCSI2SD SD card.

You can do it pretty easily if you have an SD card reader in your PC --
what I'd do is DD the image onto the SD card starting at block zero (there
are numerous dd-like tools for windows for doing this sort of thing).  Then
configure the SCSI2SD to present the first N sectors of the SD card (where
N is the number of 512-byte sectors in the CD image) as a CD-ROM, and use
the rest of the SD card for disks.

- Josh

>> Is it possible to use the SCSI2SD on a microPDP-11 under RT-11? I ask
>>> because of the disk size limit under RT-11.
>>> Doug

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