[rescue] zuluscsi wide sca80 or scsiknife sca as replacement to hd in sun ultra 60

[Nathan Raymond]

On Wed, May 27, 2026 at 1:40 PM Dave McGuire via rescue <rescue at sunhelp.org>
wrote:

> On 5/27/26 10:15, Mouse via rescue wrote:
> >> It's not an emulator when it's being used as an ordinary mass storage
> >> device.  When it's configured with a tape device, that *is* an
> >> emulation, since it's faking the tape semantics, like move forward,
> >> move backward, write tape mark, etc.
> >
> > Philosophical question, and I mean this as a discussion start rather
> > than as anything even vaguely along the lines of "that's wrong!" (if
> > for no other reason than that I would use the same terminology):
> >
> > Why is it emulation when something presents those semantics backed by a
> > file on an SD card, but not when backed by rust-coated plastic?
> >
> > Especially when it's not emulation to present a mass-storage device
> > interface regardless of whether it's backed by a file on an SD card or
> > rust-coated metal platters?
>
>    SCSI-attached tape uses the SCSI tape command set, which recognizes
> the concept of a linear tape that moves back and forth, a sequential
> access storage device...and it *moves the tape back and forth*.  A
> ZuluSCSI implementing tape functionality fakes that sequential behavior
> backed by a file on a random-access storage device.  That is emulation.
>

Agreed. I also think emulation is an appropriate term when the underlying
thing (SD card, CompactFlash, etc.) has it's own standards and protocols
and can be removed from the SCSI emulator and used via its own native
interface independent of the emulator. I consider that physical and
functional modularity to be definitionally important. If you could remove
all the circuits and firmware related to SCSI on a native SCSI block
storage device, there's not much you do with the underlying block storage
bits and pieces.

- Nate
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sunhelp.org/pipermail/rescue_sunhelp.org/attachments/20260527/620802d6/attachment-0001.html>