[comp.periphs.scsi] SCSI 2 Question

cfj@isc.intel.com (Charlie Johnson) (10/19/90)

I had thought that the SCSI 2 specifications had increased the number of
devices that you can have on a single SCSI string, but looking through
my copy of the specs dated 03/09/90, it still says 8 devices. Addresses
0-7.  Does anyone know what the real scoop is on this ??

Thanks!!


-- 
Charles Johnson
Intel Scientific Computers, MS CO1-01
15201 NW Greenbrier Pkwy
Beaverton, OR  97006           phone: (503)629-7605  email: cfj@isc.intel.com

ben@epmooch.UUCP (Rev. Ben A. Mesander) (10/19/90)

>In article <967@intelisc.isc.intel.com> cfj@isc.intel.com (Charlie Johnson) writes:
>
>
>I had thought that the SCSI 2 specifications had increased the number of
>devices that you can have on a single SCSI string, but looking through
>my copy of the specs dated 03/09/90, it still says 8 devices. Addresses
>0-7.  Does anyone know what the real scoop is on this ??
>
>Thanks!!
>
>
>-- 
>Charles Johnson
>Intel Scientific Computers, MS CO1-01
>15201 NW Greenbrier Pkwy
>Beaverton, OR  97006           phone: (503)629-7605  email: cfj@isc.intel.com


The deal is the same for the number of devices on the bus. What they
increased is the allowable number of logical units for each device. Most
disk drives and such allow thier device number to be set (via jumpers), but
are always LUN 0. Some of the ST-506 -> SCSI converters allow multiple 
ST-506 drives to appear as different LUN's on the same SCSI device. I'm
sure there's other examples, but... It would have been hard to increase the
allowable number of devices on the bus and maintain the same level of
compatability with SCSI-1 as the committee did.

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