Sun's announcement of 4/40 (warning: rather lengthy)

[Colin Plumb]

In article <10321 at brazos.Rice.edu> jh at tut.fi (Juha Heinanen) writes:
>
>In article <10253 at brazos.Rice.edu> ballen at csd4.csd.uwm.edu (Bruce Allen) writes:
>
>   - Ethernet, 2 serial, SCSI-2, and Audio I/O ports for networking and
>     peripheral connections without using SBus slots
>
> SCSI-2.  Why nothing was mentioned about it in the announcement when
> differences to Sparcstation 1+ were listed?  Or is this not a real SCSI-2
> port?  What about the internat disk.  Is it also SCSI-2?  How does the IO
> performance compare to SCSI-1 in Sparcstation 1?  Where to buy SCSI-2
> drives and how much do they cost?

The SCSI-2 standard added some high-speed features (an optional second
cable for 16-bit and 32-bit transfers and negotiation protocols, and a
fast SCSI negotiation protocol), but SCSI-2 is mostly a refinement of
SCSI-1 with a lot more required commands, better error reporting, etc.
Generally speaking, something that's SCSI-2 compliant is also SCSI-1
compliant.  (There are a few exceptions, like the "ANSI stanadrd
supported" field of the Inquiry reply, that something that's *really*
picky might choke on.) SCSI-2, though, mostly addresses the same issues
the SCSI-1 CCS did; the original SCSI-1 standard has about three mandatory
commands and zillions of optional ones.

Many manufacturers have been tracking the SCSI-2 standard; expect most new
drives to support it.

	-Colin