MicroVax II update
jsw at ieee.org
Fri Aug 5 23:05:08 CDT 2016
> On Aug 5, 2016, at 10:24 PM, Douglas Taylor <dj.taylor4 at verizon.net> wrote:
> On 8/5/2016 6:18 PM, Jerry Weiss wrote:
>> On Aug 5, 2016, at 3:48 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 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.
>> Yes - I have used the same PAK on 5.5 and 7.3.
>>>> 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...
>>>> 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.’
>> Yes. It works well with the later versions of RT11 V5.5-5.7. There are DU Handlers (MSCP) that allow a large disk to be partitioned (in the handler) into multiple drives I’ve used up to 7 in RT and 20+ in TSX+ drives at the same time. Each drive is still limited to 32Mb per partition, but you can manage up to 255 partitions (~8GB).
> I am starting to read about the SCSI2SD and it will be very useful to have it emulate multiple drives, I am thinking of one hard disk and up to 3 CDROMs, one each for 5.5, 7.2 and 7.3. If I want to use one of the SCSI id's for an image of a VMS installation CD do I make its size exactly match the size of the iso image (534MB for 7.3)?
I haven’t used the SCSI2SD to emulate a CDROM, so I gladly defer to others to who have done it. Your basic approach makes sense to me. Just write the image directly to the blocks on a SD that match the starting offset for the partition you use in SCSI2SD and leave the blocksize as 512. I used DD on Linux or OSX and its easily to pipe images on and off the SD. For Windows YMMV.
In my case I used a OSX to burn the VMS 7.3 iso to a CDROM. Then I booted it on a Microvax 3100 and built a system. From there I netbooted the MicroVax II. Since then I also was have moved and booted the same SD images on the Microvax 3100, MV II and MV III using a UC07 (no SD partitions). If you can attach the SCSI2CD to the your VAX4000 Qbus, you can try the same. I don’t think the KFQSA will work however.
> My problem is that the only computer with a SCSI interface in my possession is the VAX (and microPDP11), so I will be forced to install from an actual CD. This isn't that bad though, I installed 7.2 about 12 years ago on the VAX 4000 that I have.
> About RT-11, I had 5.4 and it allowed you to use multiple 32MB partitions, when I finish with the VAX I will start on the microPDP11. I was just curious if you could use the SCSI2SD adapter with RT-11, it looks like I can, thanks.
SCSI2SD works fine with RT11 and my UC07.
> I am at a loss to figure out how to get data onto the SD card partitions outside of VMS, will simh recognize the partitions?
You can probably install cygwin on your Windows machine It has dd and other byte banging tools to facilitate the transfer. Alternately boot a Linux CDROM. The SD card itself knows not of the partitions. This geometry is stored in the SCSI2SD.
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