Those Lot Numbers are Old

The other day I was trying to decode the “lot numbers” printed on certain Seagate drives. In the meantime, I realized that those lot numbers have been in use for quite some time. They were in use around 2000, like on this Cheetah 73 made in 2001:

Seagate Cheetah label (2001)

They can be found on Seagate’s drives going back into the early 1990s, but always only on some of them—typically on higher-end enterprise drives, almost exclusively using SCSI/FC/SAS interfaces. One older example is this 1994 DEC-branded RZ25-E drive, which is definitely a Seagate-made drive and almost certainly a model ST1480N:

Digital RZ25-E (Seagate ST1480N) label

As it turns out, those lot numbers aren’t a Seagate invention. It’s something that Seagate adopted when it acquired (1989) the drive maker Imprimis, a subsidiary of CDC (Control Data Corporation).

While Seagate built a lot of drives in the 1980s, their drives weren’t particularly technologically advanced. That made them cheap and reliable, but not especially fast. CDC/Imprimis made a lot of minicomputer drives (including 8″ and larger monsters), and those drives were good performers.

In the PC arena, CDC/Imprimis Wren and Swift drives were well known. The above Digital RZ25-E alias Seagate ST1480N is in fact an improvement of the CDC Swift, CDC’s first 3.5″ drive (of course half-height, therefore with a Seagate model number starting with 1 rather than 3) which appeared circa 1988.

CDC was—like Seagate—an early adopter of SCSI, and also the first maker of dedicated IDE drives as a Compaq OEM. Seagate kept a lot of the Imprimis drives in production for several years. At least one product line, Elite (large capacity full-height 5.25″ drives), survived until about 1999.

Here’s a label on an Imprimis-branded drive from 1989 or 1990:

Imprimis drive label with lot code (1989 or 1990)

Why the uncertainty? It is clear that for recent Seagate drives, the date code refers to Seagate’s financial year, which starts in July of the previous calendar year. For example, Seagate’s 1995 financial year started on July 1st, 1994. But it’s unclear if that was already the case with the Imprimis drives. It could well have been the case with the above drive, given that Seagate completed the Imprimis acquisition in mid-1989. There is in fact clear evidence that Seagate sold drives with an Imprimis label. And they had those same lot numbers.

Whatever the exact history, the lot number designation with a date code came to Seagate from Imprimis, possibly specifically from the Oklahoma City branch of CDC/Imprimis. It was used for some, typically high-end, Imprimis and Seagate drives at least since 1989 or 1990.

Seagate appears to have stopped using the lot number labeling after their circa 2011 rebrand, though it remained in use for existing models until those went out of production. Seagate’s current (as of 2020) enterprise drives usually have a straightforward DOM (Date Of Manufacture) label.

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11 Responses to Those Lot Numbers are Old

  1. GL1zdA says:

    Maybe some day someone finds all the missing pieces and puts together HDD family trees for the manufacturers, which remain to these days. I’m curious, whether these Swift-related drives were further developed into the Hawk family of Seagate drives or was this a different design.

  2. Michal Necasek says:

    I unfortunately don’t have enough insight into this, but it is a great question. There is not a lot of public information, and I wish there were more.

    My guess is that Hawk probably is an updated Swift. As far as I can tell, Hawk replaced the Swift family drives in Seagate’s lineup in 1993-1994 as their mid-range drive. Not a high performance drive like the Barracuda, and not a huge capacity drive like the Elite, but also a notch above a “consumer” drive.

  3. Richard Wells says:

    The best source of public information would be the Disk/Trend Reports which covered the whole storage industry from 1977 to 1999. I downloaded PDF versions of those about 4 years again. I believe they were posted by the Computer History Museum. I can’t find a link to the archive now.

    It would take a lot of effort to go through the company list and find which companies purchased which drive technologies without having a company go out of business. Most of the designs purchased would be obsolete in a few years and completely new designs would be needed anyway.

  4. Michal Necasek says:

    Would you be willing to share those PDFs? I see plenty of references to the publication (“DISK/TREND Report” appears to have been the canonical name) but no sign of the actual old issues.

    There is this but the site’s front page does not look terribly promising.

  5. Richard Wells says:

    I have no problem with sharing since I am fairly certain that the CHM was publicly releasing them. I do have a slight logistical problem of a very unreliable upstream router that will make it difficult to send the collective almost 1GB rapidly.

  6. Michal Necasek says:

    If it would help, I can set up FTP upload on this site.

  7. Richard Wells says:

    I lost the contact information but point me at the destination and I will begin the process of sending.

  8. rasz_pl says:

    misconfigured Lazy Load wordpress Plugin?

    Mixed Content: The page at ‘https …../’ was loaded over HTTPS, but requested an insecure image ‘http:…..10/PA200937-768×576.jpg’. This request has been blocked; the content must be served over HTTPS.

    wp-emoji-release.min.js also points at http address and doesnt load, not that anyone needs it

  9. Michal Necasek says:

    Which URL exactly are you visiting? What browser?

  10. rasz_pl says:

    /emulating-etherlink/ , Chrome/87.0.4280.66
    It most likely happens only on long posts where the plugin decides to delay loading assets. Mozilla says:

    >If your website delivers HTTPS pages, all active mixed content delivered via HTTP on this pages will be blocked by default. … Passive mixed content is displayed by default

    so anything js triggers cant be mixed

  11. Michal Necasek says:

    Ah, with all the caching going on it probably depends on exactly who loads which page when. Thanks for the report, I’ll see if I can figure it out.

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