16700B Drive Emulation - Page 1
Forum section: electronics / testgear

author: NF6X
author_rank: Unknown
timestamp: October 02, 2025, 10:08:49 pm
content: The 9.1G IBM DPSS-309170N drive in my Agilent 16700B still works, but I'd like to preemptively replace it with an emulated drive before it fails.I was able to image it on a Linux system using ddrescue. Plain old dd was unable to image it because an I/O error occurred about 2.1G into the drive, but ddrescue was able to image it with a single 4k byte bad section. The analyzer boots normally from the hard drive and appears to work, so I'm crossing my fingers that the bad area didn't affect anything important. HP-UX appears to think the filesystem is clean, but I have not yet manually checked the filesystem.After imaging it, I tried putting both the HD image and the Ignite CD ISO on a BlueSCSI v2. The original HD is unplugged, and I changed the CD-ROM drive ID jumpers from address 1 to address 2 to get it out of the way. With the BlueSCSI, the boot process appears to hang after printing:System Console is on the ITENetworking memory for fragment reassembly is restricted to 23756800 bytesWhen booting successfully from the original HD, it would then proceed to print out the details of the root, swap, and dump logical volumes, i.e.:Logical volume 64, 0x4 configured as ROOTLogical volume 64, 0x2 configured as SWAPLogical volume 64, 0x2 configured as DUMPSwap device table: (start & size given in 512-byte blocks)entry 0 - major is 64, minor is 0x2; start = 0, size = 1024000Warning: time-of-day register time is out-of-range... and then continue booting.I don't have a lot of HP-UX experience, but I assume that bootstrapping the kernel succeeded, but then the kernel was unable to mount filesystems for some reason.Have any of y'all successfully replaced the hard drive in a 16700B/16702B with a BlueSCSI? I also have older SCSI2SD v3.0 and v4.2 boards on hand if those are known to work better.The message about time-of-day register suggests to me that I should dig around to find a presumably bad RTC battery.

author: dorkshoei
author_rank: Frequent Contributor
timestamp: October 02, 2025, 10:15:25 pm
content: I did it with a zuluscsi.I also made a new blank aluminum plate that covers the rear slot for the multi-frame module. It had a cutout for a SDcard extender. I ran the cable for the extender back from the read to the zuluscsi card. So now I can swap SDcards without having to open up the unit.

author: NF6X
author_rank: Unknown
timestamp: October 02, 2025, 10:19:36 pm
content: Hmm. I thought that BlueSCSI was a fork/derivative of zuluscsi, so I wonder what's going wrong for me.Installing it in place of the multi-frame module blanking plate sounds like a nice way to do it. I may do the same, once I figure out how to make it work.I found the coin cell hiding under the network card, so I ordered a replacement.

author: dorkshoei
author_rank: Frequent Contributor
timestamp: October 02, 2025, 10:22:43 pm
content: My coin cell was bad also.I didn't mess with the drive ids. I fabbed an adapter plate, removed the spinning scsi disk and replaced it with the ZuluScsi using the same scsi id.IIRC I did a clean install from cdrom to the ZuluScsi.

author: NF6X
author_rank: Unknown
timestamp: October 02, 2025, 10:32:40 pm
content: I'll try doing a clean installation onto a new blank image.

author: NF6X
author_rank: Unknown
timestamp: October 02, 2025, 11:06:10 pm
content: Grr. It fails to boot the ISO image.

author: NF6X
author_rank: Unknown
timestamp: October 02, 2025, 11:30:29 pm
content: Aha! BlueSCSI was using its default block size of 512 bytes for the ISO image. I just needed to rename the file to change the block size to 2048 bytes, and now the installer is running on the analyzer. Fingers crossed...

author: dorkshoei
author_rank: Frequent Contributor
timestamp: October 02, 2025, 11:58:42 pm
content: Quote from: NF6X on October 02, 2025, 11:30:29 pmIt sounds like you've put a hard drive image and CD image onto the bluescsi and are having it emulate multiple scsi devices. I booted the CD from the physical CD drive :+)

author: NF6X
author_rank: Unknown
timestamp: October 03, 2025, 12:02:29 am
content: Yes, exactly. I couldn't be bothered to find blank media and a drive to write it with.The installer has been sitting there for a long time after promising to install B.10.20 on the system. I hope something is actually happening.

author: NF6X
author_rank: Unknown
timestamp: October 03, 2025, 01:07:26 am
content: After about 1.5 hours with no obvious activity, I shut down the system and examined the hard drive image. It does not appear that anything was written to the hard drive image by the installer, so I think the installer probably hung right after indicating that it was about to install the OS.

author: NF6X
author_rank: Unknown
timestamp: October 03, 2025, 04:12:03 am
content: I gave up on getting the BlueSCSI to work in my 16700B, and instead tried an old SCSI2SD v4.2 that I had gathering dust. With the SCSI2SD installed in place of the original HD, I was able to boot an Ignite CD that I burned from the ISO file and then perform a fresh installation onto the SCSI2SD.

author: NF6X
author_rank: Unknown
timestamp: October 03, 2025, 09:39:23 pm
content: I made a 3D printed bracket to mount the SCSCI2SD in place of the original drive. There's a pocket in the printed bracket under the SCSI2SD where I stashed the termination resistor packs in case I later repurpose this SCSI2SD in something where they're needed. I'll share the bracket model if anybody needs itThe original drive mounts on a sheet metal bracket which installs into the instrument with two pins which slot into keyhole shaped holes, and two screws to secure it in place. I reused the original screws to mount my printed bracket, and I used M3 socket head cap screws in place of the pins.I could not put the SCSI2SD's IDC header in the same position as the adapter on the original drive because the CPU card is in the way, but it's close enough that the ribbon cable still fits.I used an "industrial" microSD card in the SCSI2SD, but I wonder if it will last a long time with HP-UX scribbling all over the swap partition and whatnot? At least I can use the instrument without worrying about the original spinning rust hard drive failing at an inconvenient moment, and I saved an image of the emulated drive right after performing a fresh installation from the Ignite CD.

author: MarkL
author_rank: Unknown
timestamp: October 04, 2025, 07:00:16 pm
content: I also tried a SCSI2SD in a 16700B series (16702B, to be exact), and I found the performance was less than the original SCSI "spinning rust" hard drive. It was a SCSI2SD v5, so different than your v4.2.If performance is of interest, you might want to perform a couple of comparison tests. Boot time is where I noticed it the most, around 15-20% longer. FYI.