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Re: [TCLUG:17673] LBA mode





On Mon, 15 May 2000 Nick.T.Reinking@supervalu.com wrote:

> No, no.  I'm pretty sure that SCSI devices have
> always used LBA as its drive addressing scheme.

Working Draft of X3T9.2 Project 375D (rev10L, as of 7/sep/93):

Information Technology -
Small Computer System Interface - 2
ISO/IEC 9316-1
(yes, boys, the official document, right here in my lap) :)

Section 7, "SCSI commands and status,
Subsection 7.2.3: "Logical Block Address", page 71 in the TOC (actually page 74)

 -=-
1.2.3 Logical block address.

The logica block address on logical units or within a partition on device
volumes shall begin with block zro and be contiguous up to the last logical
block on that logicl unit or within that partition.

A six-byte command descriptor block contains a 21-bit logical block address. 
The ten-byte and the twelve-byte command descriptor blocks contain 32-bit
logical block addresses.  Logical block addresses in additional parameter
data have their length specified for each occurence.  See the specific
command descriptions.

 -=-

There.  LBA. in SCSI, as of rev. 2 (which is quite old now) :)

Nick, I'm absolutely certain you're right. :)

Now, it doesnt really matter who had LBA first.  What matters is that
everyone knows the truth and there are no misunderstandings because of lack
of knowledge.  The use of LBA should have been done from the beginning (MFM
drives) IMHO, but that would require the BIOS programmers to do math, and
who wants to do that? :)

-David