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Offset<br />
64 (40) 2<br />
Bytes and<br />
Alignment<br />
66 (42) 1<br />
67 (43) • 4<br />
71 (47) • 1<br />
72 (48) 7<br />
79 (4F) ••• 7<br />
86 (56) •• 7<br />
93 (5D) • 8<br />
101 (65) • 5<br />
106 (6A) •• 5<br />
111 (6F) • 5<br />
116 (74) 8<br />
124 (7C) 2<br />
126 (7E) •• 2<br />
128 (80) 2<br />
130 (82) •• 2<br />
132 (84) 3<br />
135 (87) ••• 5<br />
FORMAT 2 -- INDEX DATA SET CONTROL BLOCK<br />
Field<br />
Field Description, Contents, Meaning<br />
DS2NOBYT<br />
DS2NOTRK<br />
DS2PRCTR<br />
DS2STIND<br />
x •• x xx ••<br />
• 1 ••<br />
. . 1.<br />
• . 1.<br />
••• 1<br />
DS2CYLAD<br />
DS2ADLIN<br />
DS2ADHIN<br />
DS2LPRAD<br />
DS2LTRAD<br />
DS2LCYAD<br />
DS2LMSAD<br />
DS2LOVAD<br />
DS2BYOVL<br />
DS2RORG2<br />
DS20VRCT<br />
DS2RORGl<br />
DS2NIRT<br />
DS2PTRDS<br />
Number of bytes needed to hold the highest-level<br />
index in main storage.<br />
Number of tracks occupied by the highest level index.<br />
Number of records in the prime data area.<br />
status indicators.<br />
(Reserved bits)<br />
Key sequence checking is to be performed •<br />
An initial load has been completed •<br />
Last block full •<br />
Last track full •<br />
Address of the first track of the cylinder index in<br />
the form MBBCCHH.<br />
Address of the first track of the lowest level master<br />
index in the form MBBCCHH.<br />
Address of the first track of the highest level index<br />
in the form MBBCCHH.<br />
Address of the last record in the prime data area, in<br />
the form MBBCCBHR.<br />
CCHHR of the last normal entry in the track index on<br />
the cylinder containing the last prime data record of<br />
l:he data set.<br />
CCHHR of the last index entry in the cylinder index.<br />
CCHHR of the last index entry in the master index.<br />
Address of the last record written in the current<br />
independent overflow area, in the form MBBCCHHR.<br />
Number of bytes remaining on the current independent<br />
overflow track.<br />
Number of tracks remaining in the independent<br />
overflow area.<br />
Number of records in the overflow area.<br />
Number of cylinder overflow areas that are full.<br />
HHR of the dummy track index entry.<br />
Pointer to format 3 DSCB if a continuation is needed<br />
to describe this data set. This pointer has the<br />
format CCBBR.<br />
Format 2 (Index) DSCB 179
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