5 ms·

An interesting point that isn't made super clear in the article: ATAPI basically _is_ SCSI, just encapsulated in ATA commands over an ATA bus. This is possible

An interesting point that isn't made super clear in the article: ATAPI basically _is_ SCSI, just encapsulated in ATA commands over an ATA bus. This is possible because SCSI is more a network protocol with a lot underlying physical encapsulations. The PI in ATAPI stands for [SCSI] Packet Interface. So it's no wonder that ATAPI killed off SCSI CD drives in PCs. Since it _was_ SCSI, it really just killed off having to buy an extra host bus adapter card to send the same command set.

Turing_Machine 5y ago
> it really just killed off having to buy an extra host bus adapter card to send the same command set. Sometimes that stuff could get pretty baroque. Back in the day I had a 20 MB HD for my Atari 8 bit computer, which involved an adapter from the Atari proprietary bus to SCSI/SASI, then a second adapter from SCSI to the MFM HD interface. You needed one of the custom DOSes to make use of it, as the standard Atari DOS had never envisioned things like hard drives.
- boondaburrah 5y ago
  We had a lot of SCSI devices in my house, and I think maybe like, 2 devices had the same connector. Even ZIP and JAZ, both by iomega, couldn't agree. The Atari ST in my place also has an ACSI connector, which is my guess, SCSI but yet more different somehow. At that point I didn't even want plug'n'play or hotplug because getting something set up once was enough for you to never desire to change it.
  - wazoox 5y ago
    I still have a huge crate of SCSI cables for my obsolete gear. Stuff like 25 pins to 50, 50 to 68, 68 to 80 pins, HVD and LVD cables with a bunch of various connectors, cables with integrated passive or active terminators, terminators that only terminate the high bits, cables with 3 connectors (yes, really) for devices with only one SCSI port, etc. Like the old saying goes, "there are valid technical reasons that demand that you sacrifice a black goat here and there to your SCSI chain".
  - xattt 5y ago
    SCSI was the unobtainium of my childhood. There was one day where we had a borrowed SCSI card in the family computer for a Zip drive and a scanner and I felt like I lived in the future for a brief moment.
    - Turing_Machine 5y ago
      SCSI was definitely whizzy for its day, but man, was it ever finicky to get working and keep working. As a previous commenter noted, if you got a setup that worked you were reluctant to change anything.
samstave 5y ago
it woulg be wonders if you could give a history of the JAZZ drive and the other iomega things https://en.wikipedia.org/wiki/Jaz_drive https://en.wikipedia.org/wiki/Jaz_drive
- kstrauser 5y ago
  Ah, Jaz. My college buddy had one and we christened it the WORN Drive: Write Once, Read Never.
  - samstave 5y ago
    Love it... We can say same of DATA "Dicussed, Archived, Translated, Attributed (Falsely)"
  - mbreese 5y ago
    I had one and it was horrible. It was a fancier version of /dev/null. I had a bad disk once and whatever happened affected the drive head. This of course meant that every other disk I had was then similarly corrupted. I know people that used many Zip drives and were quite happy with them, but I never trusted Iomega again after that.
    - JaimeThompson 5y ago
      The Iomega click of death! https://en.wikipedia.org/wiki/Click_of_death#Iomega_Zip_drives https://en.wikipedia.org/wiki/Click_of_death#Iomega_Zip_driv...
userbinator 5y ago
USB Mass Storage (bulk only, at least) is also SCSI-based.
- formerly_proven 5y ago
  The old USB mass storage class was custom, but USB 3.0 and up enclosures should do UASP (USB Ander SCSI Protocol).
  - mmastrac 5y ago
    I assume you mean "USB Attached SCSI Protocol" :)
  - userbinator 5y ago
    No, it's always been SCSI: https://en.wikipedia.org/wiki/USB_mass_storage_device_class#Device_access https://en.wikipedia.org/wiki/USB_mass_storage_device_class#... UAS is yet another variant of passing SCSI commands through USB.
    - formerly_proven 5y ago
      Thanks, TIL. Always thought the new thing about UASP was direct SCSI support, but it actually seems like the main problem with BOT was it being fully synchronous, so only one request in flight at any given time.
chadcatlett 5y ago
To continue the circle of life there is SCSI/ATA translation for tunneling ATA in SCSI. https://en.wikipedia.org/wiki/SCSI_%2F_ATA_Translation https://en.wikipedia.org/wiki/SCSI_%2F_ATA_Translation
- pajko 5y ago
  Hard disks attached to the system as an ordinary mass storage device tend to disappear completely from the bus in case a bad sector has been hit. Learned about this while building RAID over USB at one of my former employers (don't ask). While SAT is virtually a passthrough over USB avoiding such disappearances and its presence is mandatory in, for example, data recovery scenarios. Before(?) SAT, there was Cypress' ATACB for the same purpose: https://www.cypress.com/documentation/datasheets/cy7c68300c-cy7c68301c-cy7c68320c-cy7c68321c-ez-usb-at2lp-usb-20-ataatapi https://www.cypress.com/documentation/datasheets/cy7c68300c-...

Turing_Machine 5y ago

> it really just killed off having to buy an extra host bus adapter card to send the same command set. Sometimes that stuff could get pretty baroque. Back in the day I had a 20 MB HD for my Atari 8 bit computer, which involved an adapter from the Atari proprietary bus to SCSI/SASI, then a second adapter from SCSI to the MFM HD interface. You needed one of the custom DOSes to make use of it, as the standard Atari DOS had never envisioned things like hard drives.

boondaburrah 5y ago
We had a lot of SCSI devices in my house, and I think maybe like, 2 devices had the same connector. Even ZIP and JAZ, both by iomega, couldn't agree. The Atari ST in my place also has an ACSI connector, which is my guess, SCSI but yet more different somehow. At that point I didn't even want plug'n'play or hotplug because getting something set up once was enough for you to never desire to change it.
- wazoox 5y ago
  I still have a huge crate of SCSI cables for my obsolete gear. Stuff like 25 pins to 50, 50 to 68, 68 to 80 pins, HVD and LVD cables with a bunch of various connectors, cables with integrated passive or active terminators, terminators that only terminate the high bits, cables with 3 connectors (yes, really) for devices with only one SCSI port, etc. Like the old saying goes, "there are valid technical reasons that demand that you sacrifice a black goat here and there to your SCSI chain".
- xattt 5y ago
  SCSI was the unobtainium of my childhood. There was one day where we had a borrowed SCSI card in the family computer for a Zip drive and a scanner and I felt like I lived in the future for a brief moment.
  - Turing_Machine 5y ago
    SCSI was definitely whizzy for its day, but man, was it ever finicky to get working and keep working. As a previous commenter noted, if you got a setup that worked you were reluctant to change anything.

samstave 5y ago

it woulg be wonders if you could give a history of the JAZZ drive and the other iomega things https://en.wikipedia.org/wiki/Jaz_drive https://en.wikipedia.org/wiki/Jaz_drive

kstrauser 5y ago
Ah, Jaz. My college buddy had one and we christened it the WORN Drive: Write Once, Read Never.
- samstave 5y ago
  Love it... We can say same of DATA "Dicussed, Archived, Translated, Attributed (Falsely)"
- mbreese 5y ago
  I had one and it was horrible. It was a fancier version of /dev/null. I had a bad disk once and whatever happened affected the drive head. This of course meant that every other disk I had was then similarly corrupted. I know people that used many Zip drives and were quite happy with them, but I never trusted Iomega again after that.
  - JaimeThompson 5y ago
    The Iomega click of death! https://en.wikipedia.org/wiki/Click_of_death#Iomega_Zip_drives https://en.wikipedia.org/wiki/Click_of_death#Iomega_Zip_driv...

userbinator 5y ago

USB Mass Storage (bulk only, at least) is also SCSI-based.

formerly_proven 5y ago
The old USB mass storage class was custom, but USB 3.0 and up enclosures should do UASP (USB Ander SCSI Protocol).
- mmastrac 5y ago
  I assume you mean "USB Attached SCSI Protocol" :)
- userbinator 5y ago
  No, it's always been SCSI: https://en.wikipedia.org/wiki/USB_mass_storage_device_class#Device_access https://en.wikipedia.org/wiki/USB_mass_storage_device_class#... UAS is yet another variant of passing SCSI commands through USB.
  - formerly_proven 5y ago
    Thanks, TIL. Always thought the new thing about UASP was direct SCSI support, but it actually seems like the main problem with BOT was it being fully synchronous, so only one request in flight at any given time.

chadcatlett 5y ago

To continue the circle of life there is SCSI/ATA translation for tunneling ATA in SCSI. https://en.wikipedia.org/wiki/SCSI_%2F_ATA_Translation https://en.wikipedia.org/wiki/SCSI_%2F_ATA_Translation

pajko 5y ago
Hard disks attached to the system as an ordinary mass storage device tend to disappear completely from the bus in case a bad sector has been hit. Learned about this while building RAID over USB at one of my former employers (don't ask). While SAT is virtually a passthrough over USB avoiding such disappearances and its presence is mandatory in, for example, data recovery scenarios. Before(?) SAT, there was Cypress' ATACB for the same purpose: https://www.cypress.com/documentation/datasheets/cy7c68300c-cy7c68301c-cy7c68320c-cy7c68321c-ez-usb-at2lp-usb-20-ataatapi https://www.cypress.com/documentation/datasheets/cy7c68300c-...