Quantum ACL 4/52, Дополнительное руководство

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ACL 4/52 Software Interface Guide
Document 6211225-03
Version 3.0
3-66 SCSI Interface
There are four different types of element descriptor blocks, one for
each type of element. There are several fields which are found in more
than one type of element descriptor as well as fields which are unique
to an element descriptor.
The fields found in more than one type of element descriptor have
been indicated by the same name in the illustrations and descriptions
that follow.
The format of an element descriptor for an element of the medium
transport element type is shown in Table 43.
Table 43: Medium
Transport Element
Descriptor
Bit/Byte 7 6 5 4 3 2 1 0
0
(MSB)
Element Address
(LSB)
1
2
Reserved (00h) Except Rsvd
(0)
Full
3
Reserved (00h)
4
Additional Sense Code
5
Additional Sense Code Qualifier
6
Reserved
(000000h)
7
8
9
SValid
(0)
Invert
(0)
Reserved
(00h)
10
Source Storage Element Address
(0000h)
11
12
-
47
Primary Volume Tag Information (if present)