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Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure LRDA Locate Record (Extended) data area
0000 0 Bitstring 16 LRDAREA (0) Locate record data area
Byte 0 (Operation byte)
Although defined as BITs, the contents of the
operation byte are, architecturally, multiple
codes.
0000 0 Bitstring 1 LRDOP Operation byte
11.. .... LRDOR X'C0' LRDOR Operation byte, bits
0 and 1 ------- Codes for use
with LRDOR
.... .... LRDORCA X'00' LRDORCA Orient on count
area
.1.. .... LRDORHA X'40' LRDORHA Orient on home
address
1... .... LRDORDA X'80' LRDORDA Orient on data area
11.. .... LRDORIX X'C0' LRDORIX Orient on index
-------
..11 1111 LRDOOC X'3F' Operation byte, bits 2
through 7 ------- Codes for use
with LRDOOC
.... .... LRDOCOR X'00' Orient
.... ...1 LRDOCWD X'01' Write data
.... ..11 LRDOCFW X'03' Format write
.... .11. LRDOCRD X'06' Read data
.... 1.11 LRDOCWT X'0B' Write track
.... 11.. LRDOCRT X'0C' Read tracks
...1 .11. LRDOCR X'16' Read -------
Byte 1 (Auxiliary byte)
0001 1 Bitstring 1 LRDAUX Auxiliary byte
1... .... LRDAVTLF X'80' LRDAVTLF Validate transfer
length factor
.1.. .... LRDATLFS X'40' LRDATLFS (TM) Transfer
Length Factor Scope
..1. .... LRDICCWV X'20' LRDICCWV (TM) Imbedded CCW
Op Code Valid
...1 .... LRDCBTMW X'10' LRDCBTMW (TM) CRC on track
boundary (WRITE)
.... 1... LRDCBTMR X'08' LRDCBTMR (TM) CRC on TCW
boundary (READ)
.... .1.. LRDILRCV X'04' LRDILRCV (TM) Imbedded Loc
Record Count is valid
.... ...1 LRDARCS X'01' LRDARCS Read count suffix
Byte 2 (Zeros -- Locate Record)
Byte 2 (Imbedded CCW op code -- Loc Rec Extended)
0002 2 Bitstring 1 LRDZEROS Must be zeros
.... ..1. LRDICCW LRDZEROS LRDICCW (TM) Imbedded
CCW Op Code (LRE only)
Byte 3 (Record count)
0003 3 Bitstring 1 LRDRECCT Record count
Bytes 4 through 7 (Seek address)
0004 4 Bitstring 4 LRDSEEK (0) Seek address (CCHH)
0004 4 Bitstring 2 LRDSCC CC of CCHH
0006 6 Bitstring 2 LRDSHH HH of CCHH
Bytes 8 through 12 (Search argument)
0008 8 Bitstring 5 LRDSRCH (0) Search argument (CCHHR)
0008 8 Bitstring 4 LRDRCCCH (0) Cylinder and head (CCCCcccH)
0008 8 Bitstring 2 LRDRCC CC of CCHHR
000A 10 Bitstring 2 LRDRHH HH of CCHHR
000C 12 Bitstring 1 LRDRR R of CCHHR
Byte 13 (Sector number)
000D 13 Bitstring 1 LRDSECT Sector number
Bytes 14 and 15 (Transfer length factor)
000E 14 Bitstring 2 LRDTLF Transfer length factor
Length equates
00000010 LRDBSIZE *-LRDAREA Size of LRDA in bytes
00000002 LRDSIZE ((*-LRDAREA)+7)/8 Size of LRDA in
DWs
Bytes 16 through 19 (Locate Record Extended)
For Transport Mode support
0010 16 Bitstring 1 LRDXILRC (TM) Imbedded Locate Record Count
0011 17 Bitstring 1 LRDXOP (TM) Extended Operation Byte
..1. ..11 LRDXUT X'23' LRDXUT Update Tracks
0012 18 Bitstring 2 LRDXPLEN (TM) Extended Parameter Length
Bytes 20-nn (Locate Record Extended Parameters)
For Transport Mode support
0014 20 Bitstring 1 LRDXPARM (0) (TM) Extended Parameters
00000014 LRDXBSZ *-LRDAREA Size of Extended LRDA
in bytes
00000003 LRDXDSZ (LRDXBSZ+7)/8 Size of Extended
LRDA in DWs
DSECT for mapping each Imbedded Locate Record entry
For Transport Mode support
Hex Dec Type/Val Lng Label (dup) Comments
---- ---- --------- ---- -------------- --------
0000 0 Structure LRDXILRE Locate Record (Extended) data area
0000 0 Bitstring 5 LRDXSRCH (0) Search argument (CCHHR)
0000 0 Bitstring 4 LRDXCCCH (0) Cylinder and head (CCCCcccH)
0000 0 Bitstring 2 LRDXCC CC
0002 2 Bitstring 2 LRDXHH CC
0004 4 Bitstring 1 LRDXR R
0005 5 Bitstring 1 LRDXCT Count
0006 6 Bitstring 2 LRDXTLF Transfer length factor
00000008 LRDXILRB *-LRDXILRE Byte size of Imbedded
LR entry
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